Robot of Sherwood is penned by Mark Gatiss so we expect something a little strange for the Twelfth Doctor. The title would seem to give a substantial clue to the story – this won’t be the actual Robin Hood and the robots probably mean some sort of re-creation.
I expect the Merry Men et al. to believe themselves to be the Lincoln Green heroes and also a moment of ambiguity at the end. Beyond that this seems to be an episode designed more to entertain. Expect Missy to pop up and collect the soul of the Sheriff at the end!
I chose the arrow in the TARDIS picture to point out a principle of the show:
The TARDIS is impervious to normal material unless it makes a dramatic or visual statement.
Normally an arrow wouldn’t stick into the TARDIS shell, but let’s face it, the image is good and well-timed to the dialogue.
More after transmission!