Michael stopped his car right in front of Lisa's apartment gate. He could have driven inside, but he didn't want to tip her off by drawing too much attention. He didn't want to be here, but Olivia had insisted and pleaded for him to pay Lisa a visit as soon as possible. Olivia feared that Lisa might harm herself, and while he had been concerned at first, Michael couldn't care less if Lisa jumped off a bridge when Olivia narrated the entire ordeal to him. Regardless, he was here now, so he might as well just get the job done.
Taking in a deep breath, he alighted from the vehicle and walked straight to Lisa's apartment. Without knocking, he pushed the door in, and luckily for him, it had not been locked. It wasn't like Michael to just barge into someone's home without knocking, but it was crucial that he didn't tip Lisa off in any way. She could have locked him out if he had knocked and announced his presence.