Larry Anthony

After landing on planet M-113, the Enterprise is stalked by a creature which can assume the shape and form of anyone it chooses and which kills by removing the entire salt content of its victims' bodies.

Capt Kirk investigates the penal colony on Tantalus when a prominent doctor, claiming patient abuses, smuggles himself on board the Enterprise.

Illya discovers a baffling murder with three suspects when he probes suspected infiltration of a U.N.C.L.E. survival school.