Complex sentence: However, just as they are about to leave to go the factory and test the program, Milly and Tamiya enter Jeremie's room, reminding him that he promised the two of them an expose on the life of one of Kadic's best students.
Split into simpler sentences: However, just as they are about to leave to go to the factory and test the program, Milly and Tamiya enter Jeremie's room. They remind him that he promised them an expose on the life of one of Kadic's best students.