You can find this one free on Amazon to download for Kindle or PC Kindle. It's also available in .pdf on Rachel Vincent's site. And... you can download the audio for it at Audible for free, read by the same girl who reads the other Kaylee books.
For a freebie, it's amazing. I'd have paid to read this and not have been disappointed I spent the money, but this is a great thanks from Rachel Vincent for her readers. This is definitely one of the best series in YA fiction I've read lately. You don't need to start here, but if you haven't read the others and need an incentive... this would do it.
It was supposed to be a fun day, shopping at the mall with her best friend. Then the panic attack started and Kaylee Cavanaugh finds herself screaming, unable to stop. Her secret fears are exposed and it's the worst day of her life.
Until she wakes up in the psychiatric unit.
She tries to convince everyone she's fine - despire the shadows she sees forming around another patient and the urge to scream which comes burbling up again and again. Everyone thinks she's crazy. Everyone except Lydia, that is. Another patient with some special abilities...