After passing a psychological evaluation STONEBRIDGE is back in the fold of SECTION Twenty, grateful of any purpose that distracts him from KERRY's death.
Acting on intel that places the nuclear triggers in NIGER, SCOTT and STONEBRIDGE storm an al-Qaeda in the Maghreb (AQIM) compound only to get caught in an American missile strike - retaliation for the AQIM's recent bombing of a CIA flight. Barely escaping alive, the AQIM courier escapes with the triggers and SCOTT is captured by NIGER military. Salvation arrives in from an unlikely source when CIA agent CHRISTY BRYANT frees SCOTT - he might not be happy to see his old boss, but she thinks it's about time SCOTT came home...
Back at the CRIB, RICHMOND catches STONEBRIDGE using STwenty's resources to try and locate CRAIG HANSON - it is clear at least one motivation for STONEBRIDGE's return to the unit is avenging his wife's murder.
With SCOTT back in the CRIB, SECTION Twenty traces the courier who escaped with the triggers to a hotel in NIAMEY. There, they learn that the courier, OTHMANI, is heading to the HOGGAR REGION of the ALGERIAN DESERT to deliver the triggers to fearsome AQIM leader EL SOLDAT. A routine rendition process at the hotel is compromised when STONEBRIDGE is caught in a booby trap left by OTHMANI and the courier escapes into the chaos of a local bus station where SECTION Twenty lose him. SCOTT begins to question the wisdom of allowing his friend back into the field.
RICHMOND covers for STONEBRIDGE's mistake with DALTON, but he needs to get his head back in the game. OTHMANI has successfully hidden his face on all the CCTV footage from the bus station, which concerns SINCLAIR: this guy is too good to be a low-level operator. When BAXTER intercepts an un-coded phone call from OTHMANI informing a contact that he's being kidnapped by TUAREG WARRIORS, SCOTT and STONEBRIDGE head to OTHMANI's last known location in the desert.
Making their way to the Tuareg camp SCOTT and STONEBRIDGE meet MARKUNDA, the fearless Tuareg leader who is holding OTHMANI hostage - they attempt to bribe her for OTHMANI's release, but MARKUNDA has arranged an auction: if the British Government wants OTHMANI, they'll have to outbid EL SOLDAT at a face-to-face auction tomorrow. SCOTT's impressed by MARKUNDA's front, despite the fact that she robustly deflects his romantic advances.
At the auction site the next morning EL SOLDAT's men arrive, but STONEBRIDGE's suspicions are aroused by their apparent compliance to MARKUNDA's demands. During the negotiations, STONEBRIDGE's vigilance pays off - he warns the others just as one of EL SOLDAT's fighters detonates the cavity bomb he's smuggled into the auction tent!
As the AQIM FIGHTERS drag OTHMANI from the tent SCOTT, STONEBRIDGE and the surviving TUAREG WARRIORS engage in a brutal fire fight, re-securing OTHMANI and killing all the AQIM terrorists. But MARKUNDA holds a knife to OTHMANI's throat: his men killed her warriors - she wants blood for blood. SCOTT persuades MARKUNDA to let OTHMANI live if she wants any money from the British Government, but upon searching the courier, realises with horror that he doesn't have the nuclear initiators in his possession.
In the CRIB, DALTON surmises that OTHMANI has used himself as a decoy: he knew SECTION TWENTY would overhear his unguarded call from the desert and follow him there, which means he must have left the nuclear triggers on the bus he boarded in NIAMEY.
The bus is headed not far from SCOTT and STONEBRIDGE's current location - they need to reach it before EL SOLDAT's men can. Using MARKUNDA's truck and bringing along JUBA and THE CAMEL, two of her most formidable warriors, SCOTT and STONEBRIDGE race to catch up with the vehicle. En route, SCOTT finally sends the CRIB a picture of OTHMANI and DALTON blanches: OTHMANI isn't a low-level terrorist; he's EL SOLDAT's half-brother and a highly-prized AQIM operative.
When they catch up to the bus, SCOTT and STONEBRIDGE have no time to search for the triggers before they are attacked by another group of AQIM fighters. OTHMANI attempts another escape, but STONEBRIDGE brutally disables him, much to SCOTT's annoyance: they need EL SOLDAT's brother alive for leverage - what is STONEBRIDGE thinking?
There's no way SCOTT and STONEBRIDGE can battle hoards of well-armed AQIM fighters and they'll never make it to the Algerian border so dragging a young vet, YASSIR, off the bus to treat OTHMANI's wounds, the group flee in MARKUNDA's truck.
Up in the Algerian hillside, CARL MATLOCK the mercenary from Mogadishu and his most trusted soldier JESSICA KOHL observe the scene. He's not worried about SECTION TWENTY getting the triggers, not when the reclusive AQIM leader EL SOLDAT himself is watching the area - ready to launch a devastating attack at his leisure.
SCOTT's convinced their situation can't possibly get any worse, but as one of EL SOLDAT's fighters launches an RPG at MARKUNDA's truck, he's proved sorely wrong...