Sleepless In Pre-Battle! (Japanese: クレセリアＶＳダークライ！Cresselia VS Darkrai!) is the 104th episode of the Diamond & Pearl series, and the 570th episode of the Pokémon anime. It first aired in Japan on December 4, 2008 as part of a one-hour special with DP105, in the United Kingdom on April 17, 2009 and in the United States on May 2, 2009.
Ash arrives at the Canalave Gym, only to hear bad news: the Gym Leader is away on Iron Island, and the locals are all sleep-deprived due to horrible nightmares! Officer Jenny blames the Darkrai that visits Canalave City once a year; a Cresselia from Full Moon Island always drives Darkrai away, but Darkrai is early this year and Cresselia is nowhere to be found. Officer Jenny bought a Lunar Wing charm to ward off bad dreams, but it's not working. When Brock inspects it, he realizes it's just a fake made from a lacquered Pidgey feather! An investigation leads Ash and the gang to Team Rocket, who are using a nightmare-generating machine to create a market for their fake Lunar Wing charms.
Pikachu and Ash knock out Team Rocket in no time, and everyone looks forward to a good night's sleep. But that night, the nightmares return! Concerned that Darkrai may be in town after all, Jenny takes our heroes to Full Moon Island in search of Cresselia. Dawn's Swinub tracks Cresselia's scent to a cliff known as Cresselia's shrine. Sure enough, Cresselia appears, but Team Rocket's Magikarp sub pops out of hiding and snags everyone in a net. Swinub tries to fight Team Rocket to save everyone, but it's no good until it evolves into a mighty Piloswine and smashes the sub with a single hit!
As soon as Cresselia is freed, Officer Jenny asks it to help protect the people of Canalave. Cresselia flies to the city and calls Darkrai out of hiding. Darkrai is lurking near the ruins of Team Rocket's nightmare machine, almost as if it was the machine's signal that lured Darkrai to town. Cresselia challenges Darkrai, and Darkrai wisely decides to retreat. Its work done, Cresselia disappears as well. At last, everyone can enjoy a peaceful night of sleep. Ash will surely need that rest so he can start training for his Canalave Gym challenge!
Ash and his friends go to Canalave Gym, only to hear the Gym referee screaming. He comes out, telling the gang that everyone has been having nightmares, and that the Gym Leader is out training on Iron Island. Dawn decides that some shopping will cheer up the disappointed Ash, however, they find the most popular shopping area on the island is deserted. Brock sees a police station, and goes to make a move on a very tired Jenny.
At the police station, the group is told by Officer Jenny that all the people in the town are having nightmares, and that the cause of the nightmares seems to be the Pokémon Darkrai. She pulls out a Lunar Wing, telling them that even though she paid good money for it, it doesn't seem to be working. Brock examines it with a magnifying glass and finds out it's just a lacquered Pidgey feather. Jenny runs out in a rage.
Meanwhile, Meowth and Jessie are selling their "Lunar Wings". They sell their last one, so they go inside their tent and their Nightmare Machine, which they have built to scam people into buying their Lunar Wings. However Jenny hears them speaking and moves to arrest them. Pikachu uses Thunderbolt and sends them blasting off, destroying the machine.
Later that night, the group awaken to the same nightmare, and find out that the real Darkrai is nearby, and that they must summon Cresselia to stop it. They set off for Fullmoon Island, with Team Rocket following closely in their Magikarp Submarine. They plan to catch Cresselia and Pikachu as an added bonus.
On the island, the gang discovers a real Lunar Wing, and Piplup picks up a scent. However, this is only the scent of a Psyduck, so Dawn brings out Swinub. Swinub tracks down the shrine which Cresselia is supposed to appear at, and sure enough, Cresselia appears in a flash of light. Meanwhile, Team Rocket launches a missile from their sub and traps Cresselia in a net. They extend legs on the sub, then move up to the cliff where the shrine is and trap everyone but Swinub, who uses Take Down, but gets knocked back every time.
Pikachu attempts to use Thunderbolt, but only succeeds in shocking Ash. Swinub continues to attack, failing, when it evolves into Piloswine. Using Take Down, it destroys the sub, sending Team Rocket blasting off. They free Cresselia, who proceeds to battle Darkrai, who was originally drawn to the electromagnetic pulses from the Nightmare Machine. After battling, Darkrai leaves and disappears once more. With Darkrai gone, everyone can get a good night's sleep before Ash starts training for his upcoming Gym battle.
This episode aired April 17, 2009 in the UK, nearly two weeks before the US airdate.
Dawn displays the Lunar Wing that she bought in The Rise of Darkrai, marking the first reference to the events of that movie in the anime and thus making it at least partially canon. Ash's nightmare is also very similar to the one he had in the same movie.
Despite having the aforementioned Lunar Wing, Dawn still suffers nightmares when Darkrai arrives. It could imply that her Lunar Wing is not authentic.
Also, in this episode, no one knows what Darkrai is, despite some having spoken to it in The Rise of Darkrai. This is particularly shown when Ash refers to Darkrai as "a creepy Pokémon", and exclaims "so that's Darkrai!" when first seeing him.
However, this is fixed in the English dub, when Ash instead says, "Hey, it's Darkrai! So it was Darkrai after all!" This demonstrates that he did indeed recognize it.