it doesn’t make too much of a difference to read them in order! I actually typically advise people read HOWLING first, then SINNER, and then end with STRANGER. you could also read it like SINNER, then HOWLING, but STRANGER should be the last one. there’s a portion of STRANGER I wrote after HOWLING and SINNER that features characters from those books, so it’s just more fun reading in that order! but feel free to do it however you want!