Written by Sarah Dollard and directed by Daniel O'Hara, No Care, All Responsibility guest-stars Kathryn Prescott as Natasha.
But Natasha comes to the attention of Hal for a darker reason when she offers him a way to control his bloodlust and prevent him from killing innocents.
Meanwhile, Alex is positive there's something suspicious about hotel resident Captain Hatch. But the more she investigates, the deeper into danger she gets.
Damien Molony plays Hal, Michael Socha is Tom, Kate Bracken portrays Alex, and Phil Davis is Captain Hatch.
The episode is the fifth in this final series, and pictures from it were released by the BBC today:
No Care, All Responsibility airs on BBC Three on Sunday 3rd March at 10pm.