Plot hole: Enola and Tewkesbury make an unpremeditated decision to visit the Basilwether estate. This decision was made on the spur of the moment, and no-one knew about it. but when they arrive, Linthorn, who is supposed to be in London looking for Tewkesbury, is waiting in ambush to kill them. (01:32:45 - 01:34:31)
Suggested correction: Linthorn saw them in London. He travelled back to the Basilweather estate, and waited for them to slowly make their way there.
Enola and the young Tewkesbury were in London two weeks prior to Enola's forced enrollment in a boarding school where she was supposed to spend her next few years! Furthermore, there is no evidence of Linthorn having seen them.
Plot hole: Isabel's escape can happen just because it's off-screen. For it to happen, it's critical that every single guard (minus the one she kills) is inside the monitors' room, but not a single one stays behind, because it needs that no guard can see what is happening, in person or remotely. No amount of other blindly loyal fellow prisoners who are staying behind can cover not only her fully switching her clothes, but also transporting the body (who was dressed up in full, even if there was no need for that) from the middle of the room to the nearest washing machine. It also needs the paramedics to completely bail out of doing their job; she is not Hannibal Lecter, she is not wearing the face of her victim, she has just some blood smeared on her and superficial cuts.