The reunion of Endurance and the Swarm began, as it turned out, with a collision. It was not a catastrophic high-speed collision, but it certainly was no orderly and controlled rendezvous. Aïda had the presence of mind to give them about thirty seconds’ warning. Until then it had all been going well. The heptad had approached, using its thrusters to kill most of its velocity relative to the larger ship, and executed some little burns intended to bring it home to the docking port. Then Aïda announced, in a barely controlled tone of voice, that one of the thruster modules had run out of propellant and could no longer perform its function.