ABC has picked up a full season of Nathan Fillion's mystery drama Castle, adding nine more episodes to its order for the show.

The sophomore series has shown promise on Monday nights, where it airs against CBS powerhouse CSI: Miami.

Castle debuted last season to modest ratings and therefore received only an initial 13-episode commitment.

ABC still has two more 10 p.m. shows without full-season orders, The Forgotten and Eastwick. Both have averaged lower ratings than Castle against weaker competition (though also with weaker lead-ins).