The Walking Dead season 7 episode 9: The small detail you didn't notice about the midseason premiere's opening scene

*Major spoilers for season 7 episode 9 follow*

The Walking Dead season 7 has returned from its midseason break with an extra-long episode that felt like three rolled into one (read our review here).

Its opening scene was the most intriguing, however. it focused on Father Gabriel (Seth Gilliam) as he stood night watch over Alexandria - the place we last saw him in the midseason finale's post-credits scene as a mysterious hooded figure spied on him with binoculars.

The moment sees the priest looking anguished as he raids the group's pantry, steals their weapons and tanks the car up with petrol before driving away into the night.

What could he be up to? If this seemed like uncharacteristic behaviour from him, there's probably a reason. In fact, the scene offers one minor clue - being missed by many - which may tie into the episode's climactic events.

As Gabriel drives off and the show's theme music can be heard playing, the shape of a person can be seen sitting up in the passenger's seat alongside him.

It seems that something has occurred in between the post-credits scene of episode eight and the opening scene of episode nine - something that has convinced or even forced Gabriel to abscond Alexandria - and it most likely has something to do with the group surrounding Rick (Andrew Lincoln) and the gang at the end of the episode.

Why? Well, the only thing Gabriel leaves behind is his bible having written the word 'BOAT' inside - alluding to the vessel Rick and Aaron (Ross Marquand) used at the lake in the midseason finale; the same lake where they were spied on by the very person who spied on Gabriel - the figure who is most likely in the passenger seat.

It'd be cool to think this is all some kind of ploy by Gabriel to convince this unknown group that the Saviours are their common enemy - something already on Rick's mind judging by his smile - but it seems we'll have to wait until episode ten, 'New Best Friends,' to officially find out.

The Walking Dead airs tonight on FOX at 9pm