Marcella fans have lots of theories about the killer after episode seven's shock ending

**Spoilers for Marcella series two to follow**

• Meet the cast of Marcella series 2
• The real life disorder behind Marcella's black-outs

https://www.youtube.com/watch?v=MG077HFnRsA&list=PLbs-Pk9dtKb-0E-dpbT70eUHE6_o8bxd5

Throughout the series, London detective Marcella has been investigating a series of child murders, and in episode seven, she was led to the house of Nigel Stafford, who held her at knifepoint before revealing that his girlfriend Rosio was being kept captive by the murderer. This gave Marcella and her colleagues a direct line to the murderer who had been in contact with Nigel online. But an attempt to track him down led to Rosio's death.

Elsewhere, Marcella's son Edward popped round to visit his ex-girlfriend Samantha, only to be invited inside and poisoned by her mother Jane, who apparently suspected Edward of beating her daughter.

Many viewers took to Twitter to theorise as to what might be going on. Is Jane the killer? Is there a group of murderers? Why are Marcella's trousers so short? Users shared some elaborate answers on Twitter.

Check out the best ones below:

https://twitter.com/LauraGarside/status/980915070279536640

https://twitter.com/CarysWalker206/status/980926235122561026

https://twitter.com/EmmaKinsey7/status/980928740308987904

https://twitter.com/WayneyoWayne/status/980904385139085314

https://twitter.com/gemkel1/status/980898837589053447

https://twitter.com/Aaron1Thomas/status/980915111819972613

https://twitter.com/ChloeMegann/status/980929452518625281

https://twitter.com/Thom92234254/status/980916045241307144

https://twitter.com/ChloeMegann/status/980923104909250565

https://twitter.com/DavidMackayy/status/980912732345196544

Marcella series 2 concludes next Monday at 9pm on ITV