Report 8319 GRENADE 'What Price Change', originally transmitted on ITV, 19th October 1969
Written by Bill Strutton, directed by Charles Crichton

Walker and Tremayne, students at Redcliff University, fight over the removal of an anti-defence research poster. Meanwhile, Adam Strange, Hamlyn Gynt and Superintendent Shaw inspect a box of light bulbs. Shaw explains that the bulbs are mini-molotovs, to be used, according to his information, during a student demonstration at Redcliff. Shaw asks Strange to uncover the conspiracy. Strange visits the Dean and offers his services as a visiting lecturer on Criminology. Gynt registers as an American exchange student. Gynt meets Moira, a student reporter, and tells her he is interested in joining the student protesters. Moira tells Walker about Gynt.

Strange asks Evelyn to investigate Social Action Ltd. Gynt disrupts Strange's lecture, bringing him to the attention of Walker, who invites him to join the protestors. Later, in Strange's flat, Gynt analyses the composition of the light bulbs. They are made by Arthur J. Pater Enterprises. The following day, Walker warns Gynt there will be trouble at the demonstration. Meanwhile, Strange visits Pater Enterprises; Pater denies any involvement with the modified light bulbs. Evelyn obtains a job with Social Action Ltd designing posters.

Gynt, in the Dean's office, tells Strange that he no longer wants to be part of the investigation because he is beginning to be persuaded by the students' viewpoint. Strange convinces him of the danger posed by the explosive light bulbs and he agrees to continue working undercover. Gynt is seen leaving the Dean's office by Moira. Gynt explains to Walker that he was being reprimanded by the Dean. To prove his innocence, he places a protest banner on top of the Dean's house. Evelyn discovers invoices showing that Voss, the manager of Social Action Ltd, has received large amounts of money. She also learns that he has ordered army surplus equipment.

Pater helps Voss load the explosive light bulbs into an army truck. Gynt follows Walker, who greets Pater and Voss. Pater does not tell Walker what is in the light bulbs. Unseen, Gynt jumps into the back of the truck. Strange and the police have set up a roadblock to stop Voss. Voss tries to escape, but Gynt throws the light bulbs, one by one, out of the truck. The police see the explosions and Voss is caught. In Shaw's office, Walker and Gynt identify Pater. Pater and Voss are arrested and Strange and Gynt leave with Walker.