The series is about six friends and three marriage pacts.Stalker Under the Mistletoe is Kara and Callum's story. Callum has been in love with Kara for a long time and has been waiting for the conditions of their pact to be met to propose. Kara has been in love with Callum as well.When Callum shows up to propose, he finds Kara has a stalker. So he uses his skills to protect Kara as well as work up the courage to propose.