That hope faded as fast as it appeared. She felt his hardening cock in her ass crack as well and she let out a muffled squeak of protest and shifted her ass violently from one side to the other in an attempt to displace it. Perhaps she did it out of fear of being penetrated, perhaps she was revolted or perhaps it was just a reflex, but the focus of their struggle shifted comically from him trying to choke her to her trying to buck his cock out of her ass crack.
For some reason this angered him. It made him feel rejected and it hurt his ego. He felt a flash of primal rage and emitted an audible growl in response to her desperate squeaking. He pressed his hips down to pin her wriggling ass into place. Pinned flat she could not dislodge him, so she responded with a few more impotent blows to his head and enraged squeals. His erection firmly filled in her ass crack and his mind returned to the problem of getting her into his car.
However, just as he considered releasing the attempted choke to try and drag her to his car, kicking and screaming for help all the way and possibly getting noticed by a passerby, she made a mistake. She bit down on his left arm that was over her mouth. He felt the sharp pain of her little white teeth breaking his skin and he felt blood run out of his arm. The pain infuriated him, but he managed to not cry out. Now with the skin on his arm clenched in her teeth she could not scream for help and he tightened his grip with his left arm to seal her mouth shut. Then he reached around with his right hand and pinched her nose shut, effectively cutting off her air supply so she couldn't breathe.
After a few seconds she was forced to release her bite on his arm to open her mouth and draw breath and when she gasped for air, he slipped his left arm under her chin and locked in the choke. The choke cut off her scream and, more importantly, within seconds it turned her into a limp form face down beneath him on the blanket. He felt her go slack and immediately released the choke as the goal was unconsciousness rather than death.
Once he ensured she was safely asleep he deployed his duct tape. Five quick loops pinned her tiny ankles together, five quick loops pinned her thin wrists together, five loops around her thighs and five around her upper arms and torso to prevent her limbs from flopping and a strip across the mouth acted as a gag. Then he scooped her limp form up and deposited her in the trunk of his car along with the roll of duct tape. He returned to her camp and quickly collected her belongings, a blanket, a book, a hat, a water bottle, a bag, a radio, a plastic container of grapes, sunglasses and two flip flops which he put in the trunk as well.
That done he checked again to be sure she was breathing and that her heartbeat was regular. It struck him how tiny and vulnerable she looked lying unconscious and tied in the trunk of his car. His fury at her bite cooled and the Beast receded with it. He spent a few second taking in the scene and, after thinking for a second, he had a strangely detached moment where he decided he was hungry and put the grapes in the passenger seat to eat on the way home. He checked again quickly but there was no sign of a cell phone or any other electronic device and they were still alone. Nothing would show she was ever here once he left. The trunk shut with a satisfying thump.
He jumped into the driver's seat and started the car. He removed the track suit and the ski mask and that's when he noticed his arm was bleeding. He sucked the blood and wiped the wound with the track suit top. Then he grabbed a handful of grapes and shoved them all in his mouth where he noisily chewed them up as he pulled out of the parking spot. After he reminded himself not to speed or act suspiciously, he drove home purposefully and without speeding with the prize in the trunk. It had all gone so smoothly he almost relaxed before he got her inside the house, but he checked himself. Better to be safe than sorry, and he forced himself to focus on quickly and efficiently placing her unconscious body on the thin mattress in the concrete room at the bottom of the basement stairs.
She was still unconscious and looked more vulnerable and prettier than ever. Desires swirled in his head as he stared at her for a few minutes, contemplating his next move. But eventually he decided against proceeding while she was unconscious and went to have a drink while waiting for her to awake. After all, that had been the plan from the beginning. He snapped the light off at the top of the stairs and closed the basement door behind him.