The Intercept, in Numbers

GM reference — the burn math behind Scene 1. The scene plays without any of this; reach for it only when a player wants the numbers, or when a table decision hinges on the clock.

The burn

The crew’s vessel crosses the intercept diagonal on a constant-thrust brachistochrone — burn to the midpoint, flip, brake to a velocity match.

INTERCEPT SOLUTION — NJORD'S WHISPER
Range at commit:        1.2 AU
Profile:                Full burn / flip / full brake
Acceleration:           3.0 g sustained, nano-med protocol
Time of flight:         43 h 30 m
Flip:                   H+21:45 after launch
Peak velocity:          2,300 km/s
Tracking solution:      DEGRADES H+20:00
Updates after H+20:     NONE. Dead reckoning only.

The physics, for the table’s engineers: t = 2·√(d/a). At 3 g over 1.2 AU that is a shade under 44 hours, half of it decelerating. The total delta-v is obscene — this is what the fuel tanks are for — and the crew arrives near-dry: no margin for a second hard approach, just enough left for a slow, low-thrust crawl home. One pass. That’s the job.

Two facts the burn creates

They are blind. Tracking dies at H+20, and the flip is not until H+21
. The crew goes dark on new data while still accelerating — the flip itself, the most important maneuver of the trip, runs on dead reckoning. If the Whisper had changed course, they would find out by arriving at empty space with dry tanks. (She hasn’t. They can’t know that.)
The fast profile is loud — but loud is a choice, not a law. A full brachistochrone brake points the fusion flare at the destination for nearly twenty-two hours; anything aboard the Whisper that can see knows something decelerated toward her, roughly where and roughly when. That is the price of arriving fast. A crew willing to spend time can fly it differently: brake early and off-axis while still far out, cut the torch, and coast the final stretch cold and dark on a matched vector, radiators turned away. Space is vast, and a cold hull against the 3 K background is a genuine needle in a haystack — especially to a dark automated hauler that is not sweeping hard for company. That trade — time and fuel margin for near-invisibility — is the Ghost approach in Scene 1. What no one can buy back is the coarse fact that something came this way; what the crew controls is whether the Whisper ever gets a clean, targetable picture of them.

The deadline is made of rocks

The Whisper keeps burning her freight profile the whole time the crew is in transit. Contact happens at ~2.05 AU — the doorstep of the Belt. Two days later she is inside it: a dark ship under quiet thrust behind a million radar echoes, and no solution ever finds her again. This intercept threads the last clean stretch of empty space she will ever cross.

Transit timeline

Clock	Event
H+0	Solution locked. The 20-hour window opens.
H+0 → launch	Prep, gear checks, questions nobody answers. Every hour here is an hour less of tracked flight.
Launch → H+20	Full burn. Three gravities, nano-medicined, strapped into couches. Nobody walks; the exoskeletons carry what has to move.
H+20	Tracking degrades. The Whisper’s echo freezes on the plot and never updates again.
H+21	Flip — on dead reckoning. Minutes of blessed free fall. The torch swings around to point at the target.
H+43	Contact — if the math was right. Scene 1 begins here.

The second solution

The crew’s burn is not the only solution threaded on this clock. It is just the loud one.

The CSA never needed six days of quiet cross-referencing to act, because the CSA never cared what she was carrying. The undeclared rendezvous itself — Day 12, the same watch-list ping everyone got — is the whole legal case: a transport that takes on unknown cargo in deep space forfeits her protections, and seizing her stops being piracy and becomes extraction. While the lesser submind was still connecting dots, an NHA flight was already loading. No job posting, no escrow, no crew to assemble: the marines were the standby roster, and the interceptor was already fueled on a picket.

INTERCEPT SOLUTION — CSA NHA FLIGHT
Flag received:       Day 12 — the rendezvous itself. No analysis required.
                     (THESEUS needed six more days to learn WHAT she carried.
                     The CSA only needed to know that she'd forfeited.)
Asset:               Military interceptor, Mars-trailing picket volume,
                     0.86 AU from the projected merge point. Marines aboard.
Launch:              Day 13. One day of spin-up, most of it legal review.
Profile:             Burn / coast / merge. No brake leg. None.
Burn:                4 g for 76 minutes — all of it 0.86 AU out,
                     flare pointed away from her.
Coast:               180 km/s. 8¼ days. Torch cold, radiators trailing.
Merge:               Day 21.2 — about six hours after the crew's contact.
Relative velocity:   ~0. By design, not by burning.
Terminal trim:       < 2 km/s. Cold gas and one ninety-second squirt.
Tanks at merge:      Nearly full.

The physics, for the table’s engineers — and this one is pretty: the Whisper never stops her ten-milligee freight burn, so her velocity climbs a steady ~8.5 km/s per day. If you know early enough, you do not brake at all. Pick a coasting velocity V, and the merge point solves itself: t = V/a — the moment her own curve climbs up to your speed. Arrive there ballistic, and the target executes your velocity match for you. Zero-relative-velocity rendezvous, and the only torch ever lit was a 76-minute burn nine days earlier, most of an AU away, pointed somewhere else.

Why the crew could never fly this

Three stacked reasons, and none of them is skill:

Information. The merge needs a launch by ~Day 14 to catch her curve at 180 km/s before the rocks. The crew’s employer didn’t finish understanding the problem until Day 19. The CSA moved on the flag; THESEUS moved on the answer.
Basing. 0.86 AU from a standing picket versus 1.2 AU from wherever the gig economy parked them — with a tracking solution that died 20 hours after it was born. Distance plus a dead clock forces speed.
The dial. Fact #2 above — invisibility and speed are one dial turned opposite ways. The CSA had enough time to buy invisibility. The crew spent everything they had buying speed, and the price tag was a 21-hour brake flare pointed straight at her.

And the uncomfortable footnote: the CSA could have arrived first. A 4-g brachistochrone from the picket is 1.3 days — they could have been aboard by Day 14, a week before anyone. Doctrine said no. A military torch screaming onto a flagged transport in the monitored inner volume is piracy on camera; NHA work is deniable, and deniable means grabbing her at the Belt doorstep, dark, at the last clean moment the rocks allow. They picked the latest, quietest merge on the board. The crew arriving six hours ahead of them is the coincidence the Belt manufactured — every solution, fast or slow, converges on the same final stretch of empty space.

What everyone sees

Observer	Of the crew	Of the CSA
The Whisper	A fusion flare decelerating toward her for 21¾ hours. Coarse, no track after a Ghost approach — but unmissable.	A 76-minute burn nine days ago, 0.86 AU away, pointed elsewhere. Filed under traffic by everything that saw it. Functionally: nothing.
The crew	—	A low-priority contact, if anything at all — and here is the cruel part: the merge profile is designed to read as traffic. No closing burn, no intercept geometry, velocity matched to the lane — every threat filter ever written files that as a transport sharing the corridor. The assistant is not failing; it is being correctly, professionally wrong. If the crew chose the Active sweep in Scene 1 and keeps the radar hot through the boarding, the assistant holds a track the whole time — filed under transit traffic, no intercept geometry — and the reclassification just comes minutes earlier. Reward the paranoia. It buys minutes, not the outcome.
The CSA	The whole show. They spent their coast watching a fusion flare decelerate onto their salvage claim, and they merged already briefed: the claim is occupied, professionals aboard, roughly six hours’ head start. The marines do not knock.	—

One more asymmetry, and it matters in act two: delta-v. The crew spent ~4,600 km/s getting here and arrives near-dry — a slow crawl home is the entire remaining budget. The CSA spent 182. Their tanks are effectively full. If it comes to running, nobody outruns them; if it comes to chasing, they have the fuel to be patient about it.

The two clocks, merged

Day	Crew clock	Event
12	—	The rendezvous. Every watch list pings. The CSA flags her — seizable — and starts loading marines.
13	—	CSA launch. Seventy-six minutes of burn, then eight days of silence.
19	H+0	The lesser submind finishes its homework and posts the contract. Solution locked; the 20-hour window opens.
19	Launch	The crew burns. Three gravities, 43½ hours, tanks to fumes.
~21	H+43	Crew contact. Scene 1.
~21¼	Contact +6 h	CSA merge. They walk in around scene 5 or 6 — wherever the table actually is.
23	—	The Belt. Everyone’s wall.

The six hours is a suggestion, not a law of physics — the merge point slides a few hours either way with the coasting velocity the CSA chose, so put the knock on the hull where the script needs it (it lands somewhere around Scene 6; you’ll know the exact beat once the middle scenes are written). What is not negotiable is the shape: the crew arrived loud with empty tanks, and the second crew arrives silent with full ones.

The ping (however you stage the middle, it arrives like this)

The reveal is the assistant’s, and it comes in as a correction, not an alarm — because for eight days there was nothing to be alarmed about. Something like:

“Guys — I’m sorry. That transport I flagged going close by? It’s not just going close by. It’s close.”

That is the whole horror of the merge in one line: the assistant did its job perfectly. A contact sharing the lane, matched vector, no intercept burn — transit traffic, filed and forgotten eight days ago. Nothing reclassifies it until the range stops making sense for traffic, and by then the CSA is already in the crew’s lap. It never closed. It was always going to be here; the crew just never had a reason to look until now.

How the ping lands depends entirely on how they came in — and that is the Scene 1 choice cashing out:

They ghosted (Ghost approach). Then they are also the needle in the haystack — dark, cold, matched to the Whisper. The CSA merged briefed on a fusion flare, not on a boarding party they can resolve; the crew’s own stealth is now the thing buying them the only edge they’ll get. The ping is a gift of minutes: kill the lights, hold still, and decide whether to fight from concealment, hide aboard, or be somewhere the marines aren’t. Ghost bought quiet on the way in and it buys quiet now — symmetry the players earned.
They came in loud (Active sweep on a bad roll, or Ram). Then the CSA merged onto a hull that is lit, warm, and unmistakably occupied. No concealment to fall back on — the ping is just the countdown timer becoming visible. The marines know exactly where everyone is, and the crew’s only assets are position, the Whisper’s own geometry, and whatever they’ve already learned about what’s aboard.

Same six-hour clock, same knock on the hull. Whether it’s “they don’t know we’re here yet” or “they’ve known where we are for an hour” was decided back in Scene 1, by people who thought they were only choosing how to approach a corpse ship.

If you want the reveal to sting twice, let the assistant re-run its own archive after the fact: “Seventy-six minutes of four-gravity burn. Nine days ago. Mars-trailing volume. I classified it as traffic.” Beat. “It was not traffic.”