But they forgot that Tina still had those antlers that Grimmson had cursed her with. Newt made it through the door, but Tina's antlers hit the doorframe and threw her back into the room.
"Colloportus!" said Grindelwald, and the door slammed shut before Tina could even get to her feet. By the way, it turns out even Grindelwald wasn't evil enough to spread misinformation during the Spanish flu pandemic. This is canon now.
"NO!" yelled Newt. He ran to the door and tried to pull it open, but it was useless. He couldn't open it without a wand.
He turned to see Vinda lying on the floor where Theseus had stunned her. Newt snuck up to her to get her wand. Unfortunately (or fortunately, if you're rooting for the forces of evil for some reason), she woke up at exactly the wrong moment.
"Hey, what do you think you're doing?!" asked Vinda, just before Newt could grasp her wand.
"Um..." he said. "I should think that would be obvious."
"Flipendo!" she hollered, sending Newt flying across the room. Just as soon as he got to his feet, Vinda was raising her wand again. "Avada Kedavra!" she yelled.
Still being wandless, Newt had no choice but to duck and run.