He probably has a T and was slowplaying on the flop. He may also have 44 or be playing a flush draw (presumably with a queen). It looks like hero is probably behind. I can see 2 outs (A), another 2 tainted outs (TT). Maybe he's bluffing or on a draw, but it doesn't seem likely.

With 8.7-to-1 odds I don't think a call is justified. I fold.