writing myself to a corner (searching for advise)

So, as the title of this blog implides. I usually write one or two things as a hobby from time to time. I wouldn´t call myself a "good writter". none of my works are actually published, and the one i did (and still working on) is on Hiatus. in addition, i started writting recently. No more than two years from now. 

I've been trying to figure how the scene would go but i have no idea of how i should execute it. The situation is this:

Two main characters that don't know eachother are fighting a dude that controlls snakes. and while one is fighting snakes the other onem, who is weak at hand to hand combat is fighting the dude itself. 

The thing is that, they are in this magestic sky city and my aim is to make the character that is fighting the snake guy lose an arm and lose conciousness, just to be interrrogated by the other character outside that city. Here lies the problen though, as i don´t know how to get them out of there in an beliavable way, nor i have a justificattion to end an enemy off camera. 


Any advise on what should I do? any answer is recieved.

Thanks for reading. 

—V