Cause and Effect

The Enterprise explodes. Then events begin again: the senior officers play poker, Crusher hears strange voices at night, and in the Typhon Expanse a distortion appears and another starship emerges on a collision course. Each time, Picard takes Data's advice to use a tractor beam, the ships collide, the Enterprise is destroyed, and the loop restarts. Gradually the crew experience déjà vu, and Crusher records the voices, which turn out to be echoes of the crew's own final moments. Realising they are trapped in a causality loop, they try to send a message into the next cycle. In the following loop every card Data deals at poker is a three. He recognises a reference to the three pips on Riker's collar and takes Riker's suggestion instead, decompressing the main shuttlebay to push clear. The ship survives, after 17 days in the loop, and the other vessel proves to be the USS Bozeman, missing for some 90 years.