In this richly realised universe of enigmatic aliens and complex politics, one woman must untangle interlocking mysteries in a race against time. Halley, commander of the deep space station Jocasta, is desperate. Her station is blockaded by hostile creatures, communications and key systems are failing, rations are low, tensions between humans and aliens are at the flashpoint, and a foreign trader is killed by an apparently extinct monster. Halley must now solve the mystery of a locked room in closed space - before Jocasta erupts in an explosion of terror and death.