Was inbound to Hobby, LJ31. Cleared down to 3K. Out of 4, TCAS indicated a guy at 3K and closing. I leveled at 3.5 while FO was confirming w/center. Center had no one on their scope and re-cleared us to 3, but I told them neg., till we got a tally and/or the TCAS target was clear. Sure enough, popped out of a cloud and saw the 3K traffic, an Apache. Would have smoked both of us that day, had the metal detector not saved our cans. After passing, and as we were switching to twr, approach told us he finally came up on their scope.
Uhhh, yeahhh....