The second half of The Walking Dead Season 7 started off on an ominous note, though the episode as a whole was a lot more uplifting than the show has been in months. But the opening scenes of "Rock in the Road" made it clear that the hard times were far from over, even if this new mystery doesn't yet have any answers. The episode began with a shaky and skittish Father Gabriel stealing supplies and weapons before driving off into the night. By the end of the episode, he was still missing. So where did Father Gabriel go on The Walking Dead?
That question remained unanswered at the end of the episode, but there were enough curious details to fuel more than few theories. It's worth remembering that the midseason finale, "Hearts Still Beating," ended with a mysterious person lurking outside Alexandria, spying on Father Gabriel. Though the show hasn't made the connection explicit, it would make sense for there to be some kind of link between that lone stalker and Father Gabriel's sudden rushed exit from town. In fact, the one clue he left behind only serves to make that possible connection all the more plausible. Scrawled in a notebook in Father Gabriel's home was one word: boat.
The lone stalker (let's call them Boots because they were defined only by the ratty pair of boots they were wearing) had been spotted a few times in "Hearts Still Beating" — first outside a houseboat Rick and Aaron had mobbed for supplies, and then outside of Alexandria. It seemed like Boots had followed them back to the town, and may have initiated contact with Father Gabriel after seeing him outside the walls. Based on the one-word message Gabriel left behind, it seemed fair to assume he was with Boots, the probable owner of the houseboat.
But if Gabriel was with Boots, then why did he flee Alexandria alone? He wasn't accompanied by anyone when he left, but his behavior was strange, as though maybe he feared being followed; Gabriel was clearly anxious and in a hurry, even knocking things over in his haste to get out of town. His fearfulness didn't make it seem like he was joining up with Boots of his own volition, but no one was strong-arming him either. Leaving the message made it clear that Gabriel wanted to be found, yet he didn't tell anyone what was going on either.
Boots definitely could have been forcing Gabriel to leave, because he was a menacing presence in his few appearances. His boat was unoccupied but full of threatening messages — threats that Boots might be making good on now by absconding with Father Gabriel. And they might have even more power behind them than anyone could have assumed, because when Rick and co. went after Gabriel, they were ambushed by an armed group of mysterious new survivors.
Father Gabriel was still technically missing by the end of "Rock in the Road" (which is actually unfortunate now that he's become a useful member of the community), but there were enough hints to formulate some theories about what happened to him. Next week may provide more concrete answers, but right now fans can only speculate.