Mother 4 (or Mother 4: Giygas returns) is a role playing video game for the Nintendo DS. Mother 4 is the sequel to Mother 3 and is set forty years after Lucas defeated Pokey. Giygas who was the enemy in Earthbound (which is Mother 2) returns in this game.
The story revolves around a new character who is named Sheldon, Sheldon is a ten year old boy who lives in a peaceful village called Gobi Town. Sheldon lives with his parents Lawrence and Kiki, he is the only child, but has a cousin named Jonathan who has lived with Sheldon and his parents ever since he was a baby. Jonathan's real parents had been secret agents who had died in a mysterious accident. Lucas from Mother 3 is an old man in Mother 4 and is Sheldon's grandfather.
The game begins as Jonathan wakes Sheldon up in the middle of the night seeming scared, when Sheldon asks Jonathan what was wrong he tells him someone tried to break in. A dark figure breaks through Sheldon's window and Sheldon and Jonathan engage him in battle. This is the first battle in the game and the dark figure is called "???" when you engage him in battle, he is a weak enemy (only having 20 HP and can be easily beaten). Once you beat the dark figure in battle he tells you his name is Vlad and he is working for "Master Giygas". Vlad then dies and his body vanishes into thin air, Lawrence and Kiki come into the room woken up by all the noise. When they ask what was wrong Sheldon and Jonathan told them a burglar had broken in but they had beaten him up. Lawrence and Kiki are upset about the window being broken, but Sheldon and Jonathan tell them that they can just pay for a new window, then everyone goes back to sleep. The next day Jonathan wakes Sheldon and tells him that Mayor Jones (the mayor of Gobi Town) cat has gone missing and it is up to them to find it for him, so they go to Gobi Woods where the cat was last seen, looking for him. They then find that the cat is hiding in a tree from a vicious cobra who was attacking it, you then engage the cobra in battle and he is the first boss in the game with over 200 HP but his attacks are weak. After defeating the cobra a mysterious man comes and tells them "Master Giygas is impressed" and disappears. After you give the mayor his cat back the mayor somehow knows what is going on and tells Sheldon and Jonathan that long ago an alien tyrant named Giygas terrorized Earth but he was killed by a boy named Ness who had gone back in time to kill him as a fetus, as he was too powerful in the present. Despite the fact Giygas was erased completely from time and space having been killed before being born, Giygas's essence somehow survived, though it is unknown how. Giygas is still alive and wants revenge so he takes his revenge out on Earth since Ness has been dead for years. An old man comes to the mayors house, that old man is Grandpa Lucas and he tells them that Giygas has come to the village looking for Sheldon and Jonathan, so Sheldon and Jonathan confront Giygas who has possessed the body of the mayors son, Martin. They fight Giygas and it is a long and rough battle, in the end Giygas proves to be too strong for them and he kills Sheldon and Jonathan, then destroys Gobi Town. Grandpa Lucas escapes the destruction of Gobi town and hides away in the mountains where "Giygas won't find him". It is revealed that Sheldon and Jonathan survived Giygas's attack but are in a comatose state and are being taken care of by mysterious scientists who say, "We gotta save them! The world needs people like them!", the scientists work for a mysterious man whom they only refer to as "the boss". Sheldon and Jonathan recover and they soon learn that the scientists have only saved them because they wanted Sheldon and Jonathan to help them take over the world, the scientists are working for Pokey Jr. the descendant of Pokey the villain in Mother 3 and supporting character (later villain) in Earthbound. Sheldon and Jonathan try to escape but Pokey Jr. traps them inside his lab and trys to kill them. They then fight Pokey Jr. as a boss and after you defeat him, he will join your party changing his evil ways and wanting to help them fight Giygas. Many many more things happen in the game and there are lots of side quests. In the end you have Sheldon, Jonathan, Grandpa Lucas, Pokey Jr., and Martin (who has been freed from Giygas's control) in your party and you fight Giygas the final boss. After defeating Giygas he explodes and there is a celebration to celebrate Giygas's defeat.