possible bug

I've been through act2 and i have collected the three pieces for the quest but I still don't have the horadric cube. I thought I was supposed to get the cube before the pieces. Without the cube, how do you expect players to make it to the secret cow level? Thank you for your time and effort in reading my post and hopefully a dev with fix this bug.

I think the sitting guy in town is the "cube".
But I'm not sure because I always used a bandit leader as a "cube".