Verloc has contact a with man representing unspecified forces behind the sabotage campaign.  The man expresses dissatisfaction with Verloc's last attempt at sabotage, the result of which was a brief power outage that plucky Londoners shrugged off with a laugh.  The man demands Verloc do better next time.  He demands something dramatic, something that can not be ignored--a bomb in the underground on Mayor's Show Day.

     Verloc sets out to procure the bomb.  Meanwhile, Ted becomes friendly with Mrs. Verloc and Stevie, perhaps a little too friendly with the former. 

     By Mayor's Show Day Verloc knows his movements are being tracked.  In desperation, he sends an unaware Stevie to deliver a bomb-containing bird cage (and film tins) to the appointed location.  He tells Stevie not to tarry.  The items must be delivered before 1:45pm.   

     Stevie is distracted by the festivities, and, realizing he's running late, jumps on a bus.  Hitchcock focuses on the bomb and on shots of clocks showing the minutes ticking dangerously past.  Viewers know of the danger; Stevie does not. 

     Anyone hoping for a last-second rescue is disappointed.  The bomb goes off.   The bus is blown to bits, as is poor Stevie.  The lead-up to the explosion is a classic Hitchcock suspense sequence, yet many viewers of the day were upset that the young lad had not been not saved.  Hitchcock himself came to consider this a mistake.

     Mrs. Verloc discovers her husband is responsible for Stevie's death and kills him moments before yet another bomb destroys the cinema. She tries to confess but is misunderstood in the explosion's aftermath.

    Oscar Homolka's performance sets Sabotage apart from Hitchcock's other thrillers of this period.  It is not in the light, breezy style of The 39 Steps, The Lady Vanishes, or Young and Innocent.  Homolka presents in Verloc a broken man with a secret life he seems to not much understand or believe in, but who presses ahead to inevitable tragedy, resigned to cruel fate, simply because the wheels are in motion.

     Sabotage was based on the Joseph Conrad novel, The Secret Agent.   It was renamed Sabotage to avoid confusion with the title of Hitchcock's previous film, Secret Agent.