>>58662508the game takes place before, during, and after the tower burning. Act I takes place entirely before the tower gets destroyed. You recently moved to the town of ecruteak where you meet members of the city watch, 5 of which are essentially the kimono sisters each with a different eveelution. The entirety of Act I is mostly just exposition while the ending is preparing for a storm where floods are expected.
Act II opens up with you and the city watch going around helping various people escape the floods when you get news of a fire breaking out in the tower. The key moment of this story is that it deviates from the told history of how the legendary beasts were created. Flareon, Jolteon, and Vaporeon weren't the only eveelutions that died in the fire and got resurrected, Umbreon and Espeon also get revived as two never before seen legendary dogs.
The remainder of Act II and Act III cover what happened after the fire as well as why both the Umbreon and Espeon legendary dogs are left out of the story that you hear in "modern day" johto