A clatter outside made Emily look up and peer through her goggles. Mike did the same and caught her eye, shrugging. They were used to the odd scrap outside between teenagers, or a drunken brawl involving bottles and brawn. She took off her goggles and stretched. The four of them were friends as well as colleagues, all employed by the pharmaceutical giant Ravensword. The lab in Bethnal Green was an extracurricular activity. They didn’t get paid. They did it because they believed in it.

Their clandestine meeting room was affectionately known as the Squash Club, because that was where Emily and Mike told their respective spouses they were when they spent hours away from home. George wasn’t married any more, and his only child had tragically passed away. Alex was a free spirit, with no shortage of interested girls but no desire to commit just yet. His dark good looks made him hugely popular in the bars and clubs he frequented, and it gave him an exotic edge. He shared his various encounters with the others in the Squash Club, garnering advice from his elders and envy from George, who looked back nostalgically on his own youth. They were a tight unit. Like family.

There was a checklist to adhere to every evening when they shut the lab, and Mike ran through it now with Emily, who yawned again. The last job on the list was to lock the inner facility and turn off all the lights. A generator kept the incubators going, as well as the dimmed lights inside the cabinets.

The lab was like a skin inside the garage walls, and once outside, they both felt the rush of cold air. They were like lab rats themselves when they were locked inside, methodically transferring compounds from one plate to another, looking for changes that might indicate a match. Mike locked the door and secured the bolt. There was perhaps three feet of space between the outer garage and the inner lab, and they barely had room to fasten coats and pull up hoods. Despite it being June, it was late, and the sun had long disappeared.

Neither heard the main door open.

Mike was the first to be hit. A large instrument slammed into his head, splitting his skull apart and dropping him to his knees. Before Emily could scream, two hands grabbed her throat and twisted her head to one side before forcing it the other way with such force that it tore the skin around her throat, snapping her cervical spine and severing her spinal column. She fell on top of Mike.