Internal wall crack

[lewis.baker]

Hey all, so been working on stripping god awful woodchip wallpaper (3 layers in some places!!) and sorting out blown plaster in our rear bedroom, late victorian house, and came across quite a crack on the internal wall, not sure if it's something I should be concerned about and what I should look at doing for repair for it... There's no matching crack on the external wall, there's also a loose brick which looks like someone's taken out at some point and put back in rather lazily not sure if that's the source of the crack or what, crack seems to stop about half way up the wall and it mostly follows the mortar except 2 places where the crack goes through the middle of the brick.

I've attached some pics, the few tradies I've asked so far about it have just said "get a structural engineer" and don't want to have anything to do with it and I'd rather not go that route if I don't have to, I doubt they come cheap.

Any advice appreciated as always, cheers!