Dan turned his head towards Jack at the touch to his hand, but couldn't quite tear his eyes away from the memory that was coming towards him. The mallet was hefted, tested and then swung against a wall that remained in his memory of 37 years ago. The Overlook in Jack's body continued to try and convince his younger self to come closer, but Dan knew exactly where he'd been and what he was doing, and none of it was 'go see what Daddy wants'.
Normally, Dan was very good at keeping his reactions to awful things very well-hidden. He would look and act beyond calm, he didn't flail or scream or yell or anything like that. He might go a bit paler than usual, or look slightly wild-eyed, but nothing more. He had many years of practice at not-reacting to all manner of terrible ghosts and whatever they got up to, after all. But this, holy shit. Mrs Massey was the worst, yes, but this possessed version of his dad had always given her a run for her money. The Overlook using Jack as a puppet was the other half of his worst nightmare and it was now brought out of his mind, stalking across the living room towards him. And he wasn't in his own body. As the mallet hit what should have been a hotel wall, the magic that made Dan look like himself fell away, revealing Loki's body below it. And true to form, the nightmare meant that the body was dead yet again.
He needed to snap out of it, but the shock had yet to wear off.