Carlos looks up from a barely touched stack of biology essays, blinking rapidly, and he quickly nods and smiles in greeting. He’s a little bleary-eyed, like he had been on the verge of falling asleep before Robert walked in. “Afraid so. But it’s not like I really want to bring this home, either… oh!” He spots what Robert has under his arm and perks up considerably. “You remembered to bring that back! Thank you. I’d forgotten you had taken it.” He looks from the microscope to the block on the wall, eyebrows rising when he sees the time. “You’re here late too, aren’t you?”