Call Waiting

At first the sinister phone calls that Karen keeps receiving just seem like a sick joke. The kind of twisted prank her brother, Chris, would think up. But nt even Chris would go this far...
Because somebody is trying to drive Karen insane. omebody hates her so much that they want her going out of her mind...and then they want her dead...
Is there anyone Karen can turn to? Can she really trust her boyfriend, Ethan? Can she trust her own mind? Karen knows that time is running out. She knows that the next call waiting could e her last...