Airing from 9pm, the spinoff rose nearly 250k from yesterday, also adding 125k on +1. Overall, last night was a series high for the show.
Earlier at 6.30pm, the show's main outing took 1.05m (5.4%), then a repeat at 8.30pm grabbed 273k (1.2%).
EastEnders was the most-watched serial with 8.37m (38.5%), and 864k (4.3%) for BBC Three at 10pm. Earlier in daytime, Doctors managed 1.6m (20%).
Over on ITV1, Coronation Street averaged 8.03m (34%), while a double bill of Emmerdale - which saw Maisie visit Natasha in prison and Chas clash with Alicia - brought in audiences of 7.02m (35.1%) and 7.73m (33.5%).
Elsewhere, Neighbours logged 817k (10.2%) at 1.45pm, and 1.2m (8.3%) at 5.30pm, while Home and Away picked up 449k (6%) at 2.15pm, and 815k (4.6%) at 6pm, after which Fiver's first look had 389k (2%).
BARB ratings data supplied by Attentional