Martin Flanigan was a resident of the Poseidon base when it was attacked by a strange disease, a shark and the Vashta Nerada. He was working out on the underwater prarie with the base leader, Pat, when they were attacked by the gaint shark. Only Martin survived, but could neither communicate with the base nor go down to it due to Jones's strict implimentation of the quarantine imposed by Oswald. The Doctor and Amy arrived soon after, and managed to convince Jones to let them through to the base. Martin's reunion with Oswald and Dana was short-lived, as there was a failure in the base's lights and he was devoured by the Vashta Nerada. (VG: Shadows of the Vashta Nerada)