[His mouth sets into a hard line.]

I can understand not wanting to lead with him being here, but fuck, Steve, that could've come up maybe a little sooner. I'm gonna talk to him. It might involve fewer words and more sharp objects, but yeah, we've got some unfinished business. [...There might also be words, too, but if Loki--who is here, what the fuck--ends up with an arrow to the knee, well...]

Exactly how sure are we that this isn't his doing?