Lupin felt it grip him. A hunger and a fury, a yearning for blood that he didn't know how to fight. His natural instincts kicked in as his limbs extended and the hair ran back into his scalp. His pupils dilated. Breathing quickened. And he had absolutely no control.
'Remus!' Tonks yelled, appearing suddenly in front of him, gripping the front of his shirt and shaking. 'Remus, stop! Fight it!'
'Teddy,' he gasped. 'Get him out, Nymphadora. Get him out!'
Tonks struggled to keep calm. 'Teddy's asleep, Remus, let me take you outside instead. Let me take you away from him.'
Remus felt a growl erupt from his throat before he could hold it back.
Tonks turned impulsively and kissed him. He shuddered and bit back the urge to attack her. He held onto that kiss as long as he could, and then stumbled away from her, against the wall, eyes squeezed shut, the connection broken.
Tonks had tears in her eyes that she hastily shook away. 'Hold on, Remus. Remember what that feels like. That's human.'
'Help me, Tonks please,' he begged. 'I can hold on, but not for long, not for long.' He wheezed, clutching his chest. 'Just help me to the door.'
He limped, draped over Tonks' side, out of their bedroom and down the hallway to the front door.
Remus collapsed onto his knees before he had the chance to open it. He started groaning, his whole body vibrating with effort as he tried to get a handle on his transformation. 'Wolfsbane,' he managed. He thumped at the space above his heart as he panted.
'It's in the cupboard – hang on a minute – accio Wolfsbane!' Tonks flourished her wand, knocking over their umbrella stand in the process.
A small vial whizzed from the kitchen and into her hand. Stowing her wand away, she popped the bung and shoved it into her husband's trembling hands.
'Quickly, Remus,' she said, frightened. 'You're nearly transformed. It might be too late.'
'Take Teddy and get out of here,' Remus spluttered, downing the liquid. 'And call Albus.' He looked scared. 'The full moon is a day away. This shouldn't be happening now. I don't understand-'
He broke off and started making animalistic screams. Upstairs, Teddy began to cry. Tonks stood in the hallway, torn between them.
'GO!' Remus groaned, his face tortured. 'Apparate!'
Tonks saw him shudder violently and watched fur sprout across his hands. He lunged out and clawed the wall, sobbing into the plaster. That was enough. She waved her wand and appeared next to Teddy. Scooping him up in her arms, she braced herself against Lupin's cries and Disapparated.