"Hey Dad, how come you live in this biiiiiiiiiiiig house, but Mom lives in a hole in the ground?" When the mom doesn't give a satisfactory answer, the only option is to go ask the dad the same question. So here Passage is on one of her regular visits to the House of Lights, asking Flandre all sorts of out-of-nowhere questions like this one.
"You know, that is a good question. You see, while I've lived here a long time, your mother is a new arrival in this world. She doesn't seem like she wants to put down roots here, metaphorically speaking. It would be nice if she could spend more time here, it would mean I get to see you more often."
"I've been meaning to pitch the idea of somehow linking our homes together. Either through the use of her grimoires, or perhaps my magical gates. If not for her, then at least for you."
