"Terence," Ashleigh said, a vain attempt to call attention to the way his hand was tightening around herself. "Terence! Ow!" She was more worried about Higgs than her own pain, he was non-responsive and seemed to be looking more through her than at her. Even before he stilled, jerking her body to a stop as well, she knew something was wrong. Her own heartbeat increased noticeably and she could feel her pulse vibrating in her thin wrists, but she pushed that all away, dropping the hand from her shoulder to unconsciously check her handbag for her wand.
Part of her wanted to just apparate him to her flat right then and there, but Ashleigh was far too sensible to go breaking the statute unless it was a life or death emergency. And a panic attack, if that was even what this was, was not life or death. "You're safe," she said, not sure if he could make out the words over the loud music but knowing that the words would keep her voice and posture calm, which she hoped would be reassuring. "It's crowded, but no one wants to hurt you and no one is looking at us." That last might not be true, but Ashleigh was too focused on Higgs to check.
With some effort she managed to tug her hand from his, moving to his side and taking him by the elbow. "We're going outside," she informed him as she did her best to urge him off the dance floor. If Higgs didn't want to move, the chances of Ashleigh overpowering him without magic were slim to none, and trying was unlikely to help. "And then you can come back to my flat. It won't take a minute." She could have offered to take him home, but she knew where everything was in her own flat - and she knew she had lists and tools that would be helpful.