1.: The storyline starts at the clinic where you are offered to take some experimental drugs for money. Signing up for a single test starts the voluntary path and signing up for multiple tests starts the involuntary path.
2a: Advancing through the storyline voluntarily is easy, you just need to take the pill.
Taking the pill for the first time will always make you grow boobs (or grow larger ones if you already have some). Taking it again will grant you random changes that make you more feminine.
Eventually he will stop offering money and then he will stop offering the pills altogether.
After he stops offering the pills he will want to have sex if the player character is feminine enough.
Having sex with him the first time gives you a coupon you can use for a free surgery at the clinic.
Teasing him and then denying him, his reward will lead to the “Lab Freak” bad end.
2b: If you have taken the involuntary path then you will need to show up for the trial each day or get fined $100. Otherwise it’s very similar. The more feminine you get the more lecherous Dr.Marlowe becomes. You can end the storyline by agreeing to have sex with him once you have grown a vagina.
During this phase you can have your first encounter at the mall with him.
3.: After the trial is over you can keep having sex with Dr.Marlowe.
During this phase you get your second mall encounter with him.