A lesser detective would have looked for Anna in theaters, laboratories, and morgues, as she had been a ballet dancer until injury, a widely known geneticist, and had run away from a wealthy and ruthless man. They wouldn't have known she hadn't been his mistress but his secretive researcher and willing experiment. A great detective would have found this and would be already listening for the financial silences that told of corporate espionage.
Val was the best detective in the world. She understood obsession: the purchase and the coin. She sought dancing studios looking for the small and struggling that were easy to rent discreetly for a short while. Val found a dozen scattered around the city. Four confessed or bragged of having let Anna work alone in them. The first talked with pity of a broken dancer who had not been great even in her prime. The last had more questions than answers and was therefore the most informative. Who was this timewise reversed prodigy who could dance like that at such an age?
The trail disappeared there as Val had known it would. Four points, however, were enough to plot a spiral. There weren't many medical care companies at the level Anna would have used and their commitment to privacy was far above their security know-how.
Val didn't break into the room until she was sure Anna and her would be alone. Anna seemed merely asleep. Sensors were in the mattress and bedframe, the cameras were hidden (of all which Val had hijacked), and the medical equipment was tastefully kept within the walls. But she would never wake up and was not really asleep. There was frantic movement under her eyelids, a remote echo of titanic energy as her brain coordinated increasingly impossible figures no flesh and bone could draw on a physical world. She was neither conscious nor unconscious but in the narrow peak of perfect attention and would remain there until not even her modified brain could cope with the exponential perfection of her dance and she fell into the arms of a death she had discarded awareness of like she had discarded everything else slowing her down.
To some it would have inspired awe. For a detective hunting down somebody it was merely her prey. But Val wasn't working for anybody and she wasn't seeking Anna. Not really. She took a sharp strange bespoke device from a pocket and moved Anna's hair away to clear the right spot on her skull. Dance was a form of art among many and technologies could be repurposed if you knew the right people and had enough money or blackmail material. You didn't become as good as she was unless you knew everything about the endless transaction except how to want to stop. By the time Anna stopped breathing the detective was blocks away. Her mind as always was a pulsating mechanism of plans and inferences that she was already feeling uncomfortably slow.