Chloe and Dawn help the injured Cresselia. Elsewhere, Ash and Goh encounter Darkrai and follow it. The girls also run into Darkrai and the Team Rocket trio before escaping to a beach, where they eventually meet up with Ash and Goh. The Matori Matrix arrives to capture Cresselia. Darkrai appears to protect Cresselia, but it is weakened by an electric attack. Cresselia uses Lunar Dance to heal Darkrai. After Team Rocket is dealt with, Cresselia and Darkrai return to Fullmoon Island and Newmoon Island respectively. (Source: Wikipedia)
