Well, you have to introduce the characters and the boy's problem, so start with Him having an episode, opening his eyes and seeing her then explaining what his problem is
Once upon a time......................
The spring sunshine felt warm on Sianna's bare shoulders as she strolled through the park but the boy shuffling toward her made her feel uncomfortable. She knew boys found her attractive and was quietly pleased at the attention she normally received, but his fixed stare was unnerving.
As they drew closer together she realised that he wasn't actually looking at her but staring into space. His breathing became audible, ragged, and his footsteps began to falter. Then, when they were only an arms length apart he staggered, before starting to fall. Instinctively, she reached out to break his fall...