Derek had been out and about most of the morning, running errands, running in general like he did every morning. So when he jogged back into the parking lot of the warehouse that also happened to house his loft and he saw an unfamiliar car, his relaxed demeanor immediately shifted. It wasn't until he actually slipped into the building that he was able to catch a scent and, even then, it was muddled like it wasn't the only one. He caught Lydia but the rest made no sense.
Derek bounded up the stairs to the second floor where the actual loft was located and he stopped suddenly at the sound so out of place that it was impossible go miss. ...that was a baby.
Warily, Derek proceeded up the rest of the stairs and found Lydia knocking on his front door and an infant in a car seat on the floor at her feet.
"...what are you doing?" he asked, eyebrows lifted with incredulity, assuming that she had brought the baby. "Whose baby is that?"