The Prestige - I might spoil the ending so dont read this if you dont want to know what happens.?

Yeah it was his biological twin, cause yeah he didn't even really go to Tesla, or he did, but not to get that machine, but just to get the electricity thing. But yeah because he had the twin the whole movie, even though the first time you see him was like when his wife came in that room. who knows. i want to see it agian to see it you notice him before that.