Mirko made a show of tiptoeing around the Professor's living room, holding one hand up to his brow as if to ward the sun from his eyes.

"I don't know," he said out loud, turning his head back and forth. "I don't know…"

A little voice giggled from behind a nearby armchair, but Mirko pretended not to hear it. He put one hand on his hip, the other on his chin, and hummed, the sound deep and contemplative in his chest.

As he did this Martín appeared in the doorway across from him, having approached as quietly as a ghost, but he didn't come all the way into the room. He was holding a glass of pale yellow liquid in one hand, and despite the bright scent of summer and high spirits in the air, he looked faded.

"There you are," Martín said softly. Then, in a clearer voice, he continued: "Stockholm made lemonade for everyone. Do you want to come try?"

He lifted the glass, waggling it temptingly, and though the gesture seemed half-hearted Mirko laughed.

"Of course," he said. "But first, I must find Cincinnati. He is hiding."

"Hiding?"

"Yes," Mirko continued. "He is hiding very well. He is so good at hiding I cannot find him."

Cincinnati, behind the armchair, giggled again, and to his credit Martín did not look over- but he did smile slightly, and he took a step out from the shadows of the doorway, halfway into the light.

"I see," he purred. "What a predicament! If we don't find him fast, the lemonade will be all gone before he gets any. That would be terrible."

"Terrible," Helsinki repeated gravely. Then he sat down on the armchair, letting out a great sigh of defeat. "But it is impossible. I don't know where."

"I'm here, I'm here!" Cincinnati yelled, popping up from behind the chair. Mirko threw up his arms and leaned back, crying out in shock while Cincinnati laughed.

"I was here the whole time, you didn't see me!" he said, smiling widely in a way that- even though there was no biological relation- closely resembled Denver. "You're bad at this game, Uncle Helsi!"

"No, you're good at hiding, very good," said Mirko while Cincinnati bounced up and down in triumph. "Now, we should go have your mother's lemonade. After, we can both hide from Uncle Palermo. It will be fun because he will have trouble finding us."

"Now, what was that?" Martín said, smirking, as Cincinnati passed him and ran down the corridor. Mirko shrugged, and already Martín looked brighter.

Whatever was bothering him, though, Mirko didn't get a chance to find out- Martín kept busy that day, playing with Cincinnati and then helping with dinner, always keeping himself at the center of the commotion. But even though he smiled, and put on all his best charms, Mirko couldn't help but think he looked a little sad.