Outnumbered by the children, head teacher Hilary Head calls for backup from some very unusual supply teachers, and a bromance blossoms for Mr Capp.

It's Careers Day at Dockbridge High so everyone will be getting some excellent advice from careers advisor Miss Droppitt, if she can spare five minutes between her other jobs. Mark follows in Mrs Mark's footsteps, and Mr Capp changes his appearance.

There's a dog poo-traipsing intruder in the school and site manager Dave is determined to catch the culprit. Meanwhile, Mr Nasal attempts to keep his relationship with Miss Spray a secret, and Mr Konnundrum's in trouble... with his mum.