'Men in Black 3' trailer: Will Smith and Tommy Lee Jones go back in time

By the time "Men in Black 3" hits theaters in May 2012, it will have been a full decade (minus about six weeks) since the last film in the franchise debuted. So maybe it's appropriate that time travel is a central element of the new movie's plot.

The trailer for the threequel lays out the scenario: Agent K (Tommy Lee Jones) has gone missing, and J (Will Smith) is denied access when he tries to find him -- only to be told by a fellow agent (Emma Thompson) that K died 40-plus years ago. J then finds a way to travel back in time to find the young K and figure out what the heck's going on.

We're not sure that a third "Men in Black" movie is necessary, or that 10 years after the last one, whether people will go see it. But the trailer derailed some of our initial skepticism thanks to the ease with which Smith and Jones seem to step back into their roles, and the note-perfect casting of Josh Brolin as the young K. We now have a little bit of hope that this could actually be pretty fun.

"Men in Black 3" is scheduled to open on May 25. What are your thoughts on the trailer?