During a school trip, she abandons her students to meet Will Mellor’s Jimmy for an illicit rendezvous after trying to resist his advances. But her reckless decision also proves to be a deadly one.
While the pair are otherwise engaged, one of her pupils, Zac, goes missing, sparking a frantic and desperate search that ends when his body is found face down in a lake.
Now initially, the scene suggests Zac took out a kayak on his own, toppled out after losing control, and drowned as a result. But this is a Channel 5 drama, which means there are no tragic accidents.
Zac was murdered, but by who?
Is Jimmy’s son Matt responsible for his death? We know that the pair had argued prior to the excursion, the details of which are currently unknown, and Matt spent most of the trip aggravating his peer.
Did that spiral into something much more serious in Dani’s absence?
Or is another student the perpetrator? Sienna and Zac were close, but are her tears hiding a more shocking truth?
Or – and this would be a truly sinister development: did Dani’s husband (Emmet J Scanlan) kill Zac?

Tim, who is a teacher at the same school as his wife and Jimmy, and is also Jimmy’s best friend, called in sick due to migraines when the trip took place, but a scene towards the end of the episode indicates that he lied about being ill.
Holed up in his office, he begins scrubbing fresh mud off a pair of his boots, and as the score takes an eerie turn Tim’s attention is drawn to a collection of photographs on his desk featuring Zac and the rest of the football team.
Does he suspect Dani and Jimmy are having an affair and wanted to catch them in the act?
Is he a predator who has an unhealthy obsession with teenage boys, one of whom was Zac?
Or is there another, unknown reason that he was in the woods when the teenager was killed?
The Teacher season 2 continues on Tuesday 10th September at 9pm on Channel 5. Stream on My5.
Check out more of our Drama coverage or visit our TV Guide and Streaming Guide to find out what’s on. For more from the biggest stars in TV, listen to The Podcast.