The game doesn’t have an intro cutscene like the original did, so you have to piece together what is going on from the clues within the game such as the environment and Loggo’s taunts. It’s up to Banjo and Kazooie to get to him. Loggo (the toilet from Mad Monster Mansion) obtained Gruntilda’s magic and used it to create the Dreamy Depths, an area below Grunty’s Lair. The game takes place in between of Banjo-Kazooie and Banjo-Tooie, consider it kind of like a BK 1.5.