Where do I catch Mesprit in pokemon diamond?

Question

Where do I catch Mesprit in pokemon diamond?

Answer 1

lake verity. after the battle with team galactic, use surf to swim out to the cave in the middle of the lake walk inside and than you can battle mesprit. you have to battle it before you do any thing else or it will leave.    

Answer 2

Like the other person said, by lake verity after beating the elite four at the valor lakefront. Just a bit more to add though, before you go to battle it make sure you have a pokemon with the move mean look or block (to stop mesprit running away) and about 15 Dusk balls. Also make sure you save before going into the cave so you have the chance to try again. Good luck!