Tidus doesn't even realise the interruption before the 'Oh', the sound of the door not as disturbing--or maybe he was just that zoned out? But it's with it that Tidus lifts his head, a small "huh?" of his own; blinking a few times, looking left (...that's a wall, Tidus) before right, and seeing legs that lead up to--

"Huh?" A guy? Tidus stares at him curiously, then through the glass doors. "What's up? Something happened? Wait--"

That last part is more mumbled as he lifts his left wrist, a SCA band around it. "Ah-- four more minutes...!"

If Senku looks, he'll see a time ticking smaller, and indeed, around 4 minutes and 32 seconds ticking down.