Babies were intuitive. If they were crying, you tried to find out why. Usually, first things first: check their diaper. Derek didn't think it was that hard and if Lydia couldn't figure it out, he wasn't sure she was as smart as she thought she was, after all.
Derek finished opening the envelope as Lydia headed out and he pulled out the note, reading it. He read it once, twice, three times before it sunk in and the color drained out of his face. It took him the three tries to actually figure out that it wasn't just some random abandonment; he knew the woman who'd signed the note. ...if she wasn't full of it, this baby was his and he was just finding out about it — her; Daisy, apparently — now. Once Lydia came back with the diaper bag, Derek put the note back down on the desk and started digging through the bag in search of supplies he needed, trying to clear his head and concentrate on the baby girl in the car seat.
"Oh, I know, baby girl," he empathized as he unfolded the baby blanket that was tucked around her and laid it out on the desk before lifting her out of the car seat and laying her down on it. "Just...I'll get the stupid book in a minute, all right?" he asked, sensing Lydia hovering.