This is all part of the (Andromeda) strain of science-fact-fiction, a doomsday script triggered by a self-destruct plastic container which is eco-and-economically beneficial until. . . a robot goes amok in a toy department, a lunar capsule falls into space, a computer-control experiment is fouled up, and all hell breaks loose in the underground tubes. Omniverous Mutant 59 (a bacteria) feeds on plastic and just think of those vulnerable possibilities -- eyeglasses, dentures, baggies, etc. -- while London detonates and incinerates in the volatile process. The authors keep their story active and as BBC scenarists, they give priority to those audiovisual effects while the personal side of it (a broken marriage -- a romance) are subsidiary.