The Invisible Enemy

On the way to their base on Titan, a shuttle crew is infected by a mysterious entity calling itself the Swarm. The infected crew begin preparing a breeding ground for the Swarm, so that it might begin its conquest over all other living things. When the TARDIS passes by, the Doctor is also infected. Only Leela appears to be immune to the Swarm's influence. The Invisible Enemy isn't a great story. It's not particularly original, as it seems to borrow elements of Genesis of the Daleks and The Ambassadors of Death. The serial's production value is a bit of a mixed bag as well. Most of the sets are well made but the costumes and visual effects are all pretty lackluster. The Invisible Enemy is notable, however, for the introduction of K9, a robotic dog companion. It doesn't take long for Leela and K9 to strike up a friendship and the scenes of the Fourth Doctor interacting with K9 as if it were a real, flesh and blood dog are pretty funny.

Rating: Some of my best friends are humans%