[Conjoined]Extra partner

In a world with super advanced biomedical technology, where many seemingly unsolvable problems have been overcome.

On a Saturday morning at 9 o'clock, Evan Lee (age 29) was eating bread and watching a video advertisement. It was a volunteer recruitment ad that had been popping up occasionally for the past two months. Evan had always clicked "skip" until a few days ago when his girlfriend, Hannah Moore (age 25) , mentioned the volunteer recruitment to him. Intrigued by Hannah's interest, Evan decided to pay attention the next time it appeared.

The project was called "Extra Partner" and was organized by an international laboratory. In each experiment, there would be a host and an extra partner. A neural shunt device would be implanted above the host's first lumbar vertebra, and the extra partner's head, neck, and all thoracic vertebrae would be removed. They would then be connected to the host's spine via the neural shunt device, allowing the host and extra partner to share the host's entire body.

Typically, control was split with the host having 51% and the extra partner having 49%.

The experiment was divided into three time frames: seven days, one month, and irregularly (depending on the experiment's progress). And the rewards for the experiment were extremely generous, an astonishing sum.

"Well, now I understand why Hannah was so interested..." Evan said after finishing his breakfast, putting on his jacket to head out.

It was Hannah's birthday today, and she was returning from a business trip. Hannah, who had a great figure, worked as a full-time model for a women's clothing store and a women's shoe store. Normally, Hannah never went on business trips, but this time she had received a temporary invitation from another store to travel to a larger city for a new product shoot.

Evan bought a birthday cake and flowers before rushing to the airport in his new SUV. Waiting in the arrivals hall, Hannah's message informed him that her flight would land at 10:30. Unfortunately, three planes were landing at the same time, making the arrivals hall crowded.

In the bustling crowd, Evan caught sight of Hannah. She was dressed as usual in a loose white casual shirt, gray high-waisted wide-leg pants, and a khaki trench coat. As he got closer through the crowd.

Evan noticed that Hannah was wearing two mismatched high-heeled sandals, which didn't affect how she walked but looked a bit odd.

As Hannah emerged from the crowd, Evan stood frozen in place holding the birthday cake and flowers. "Oh my, Hannah actually went to participate in that 'Extra Partner' thing?!"

Hannah's body now symmetrically bore two heads, both wearing identical sunglasses. Hannah's body carried Hannah's handbag on the right shoulder and dragged their custom couple travel suitcase with the right hand, holding a phone in the left hand.

On the left side was Hannah, her long brown curly hair tied up in a high ponytail, looking around for Evan.

And on the right side...