Twins ran in the Stokes family.

John Stokes himself had a fraternal twin brother, Kurt. His wife Maureen Carter was the older sibling to identical girls named Melanie and Melissa. They had met at a twin convention in Minnesota that John and Kurt were attending and Maureen was chaperoning her sisters. Between them, there were sixteen sets of twins: siblings, cousins, aunts, uncles. John's grandfather even had a twin.

Because of this, it came as no surprise when on August 18, 1971 Maureen gave birth to her own pair of twins, her sixth and seventh children: first a girl, Rachel Jane, who was followed twenty minutes later by her brother, Nicholas James. The running joke in the family was that Rachel had been first because of her eagerness to join the world and greet everybody, while Nick, who proved to be a painfully shy child, hung back as long as possible, truly making him the youngest child of the Stokes clan.

As babies, people would marvel over the Stokes twins, claiming they'd never seen a brother and sister so in tune with one another. When one cried, the other would follow soon after. When one was sick, the other would fall ill no less than twenty-four hours later. They couldn't stand to be separated and getting them to go to school and put in different classes was so devastating to them that special arrangements were made so they could be together. In one particular incident when they were five, Nick had fallen down while roller skating outside and broken his wrist, while inside, Rachel complained of acute pains in her arm—completely unaware of Nick's accident.

Growing up, Rachel was fast to protect Nick from anything and anyone—but when they entered middle school, roles quickly reversed. Rachel proved to be a bit more promiscuous than John and Maureen would have liked, getting caught up in parties and boys. The elder Stokes children were constantly defending the honor of their littlest sister, but none fought harder than her twin.

Over the years, when the older kids washed their hands of Rachel, it was Nick who unlocked the door every night so she could sneak home discretely and lied for her. He would accompany her to certain parties and picked her up when she was too drunk to drive. When they were sixteen, it was Nick who had driven Rachel to the abortion clinic and when they were twenty, he had taken her to get her stomach pumped when she had mixed vodka and one to many sleeping pills.

Nick spent a good part of his life taking care of Rachel, until they graduated college: Nick with his bachelor's degree in criminal justice and Rachel with hers in theater. They went their separate ways. Rachel headed to California and Nick remained in Texas at the Dallas PD. They stayed in touch fervently, writing letters and emails, sending postcards, making phone calls almost daily, tearfully reuniting for every holiday and family event.

But one day, about five years ago, Rachel stopped responding to Nick's letters and returning his phone calls. He couldn't understand it. Barely a day went by when they didn't hear from one another. He called his parents and asked if they'd heard from Rachel and his mother explained that Rachel had contacted them—only to say that they wouldn't be hearing from her for awhile. She gave no explanation. This news had sent Maureen Stokes into a frenzy but was reminded by her husband that Rachel was a grown woman now, she could take care of herself.

It seemed like Rachel had disappeared from the family. She didn't show up for any Thanksgivings or Christmases or Easters. She didn't show up to the christening of their sister Grace's twins, Logan and Lily, and she wasn't present at the family reunion. And it wasn't like the family didn't try to contact her: phone numbers they dialed were answered with a recording explaining that the number had been disconnected. Letters that were written came back with Addressee Unknown scrawled on them. In five years, Nick had gotten only postcards from Rachel—short, curt and without a return address, postmarked Chicago, Florida, Indianapolis. Random and without consistency.

Having Ryder appear on Nick's doorstep was the first thing Nick had heard from Rachel in two years, when she came for an unexpected visit.

"I'm in town for a few days," she announced. She had shown up with only a small duffel bag. "Can I crash here?"

"Uh…" Nick was confused but happy. "Sure, sure. You can take my bed, I'll use my pullout."

She had suggested—no, insisted—that Nick take her clubbing that very night.

"Come on, how often are we together anymore?" she said. "I want to go out and dance. Please, Snickers?"

It was the old nickname she had called him when they were kids. He eventually relented and took her to a few places.

Nick still wasn't sure where or how, but along the course of the night, someone had handed Rachel some ecstasy. Nick didn't see her take it, but he knew all the signs: heightened energy levels, grinding of the teeth, loss of appetite, sweating, nausea, hallucinations—Rachel had the whole nine yards. She was also overly affectionate to everyone, which made Nick uncomfortable. He had to follow her around all night to make sure she didn't over-hydrate herself or get into any kind of trouble. At one point, he had lost track of her in a club called The Rocking Chair, where she disappeared into a back room with a group of people. When Nick tried to follow them, he was stopped at the door and told he wasn't allowed to enter. So he waited patiently until Rachel emerged, trashed and partially disrobed, nearly two hours later. He promptly took her home, despite her protests.

That wild night in Vegas, Nick sighed as he shook his head and sat at his kitchen table. Ryder was making a fantastic attempt of grabbing Nick's keys, just out of reach. He was making cute little grunting noises in effort.

"What? You want my keys?" Nick raised an eyebrow.

"Kaaa…" whined Ryder.

Nick remembered how easily his niece Shelly, now sixteen, was entertained simply by having a key ring jangled in front of her. "Check this out, Ryder." Nick made the keys dance, successfully catching the baby's attention. He gave a smile and made a quick grab for them. When Nick pulled them away, Ryder's face crumbled.

"Aw, man, don't cry…" Nick started to say, but it was too late. Ryder took a deep breath and let go. Nick didn't think a wail that loud could come from such a tiny baby. "Whoa now!" Nick backpedaled and quickly thrust the keys towards him. "Take the damn keys!"

Once Ryder had the key ring in hand, his cries died down and immediately stuck the keys in his mouth and began to gnaw on them. Nick filled his cheeks with air and sighed. Again. This was going to be a rough day.

How am I going to explain this one to Grissom?