A woman who thought she was casually giving up the seat next to her to a stranger froze in shock when she realized she was speaking to her best friend of almost 30 years who lives across the country. Mary King, 63, lives in Cockeysville, Maryland, while her best friend, Cary Sandoval, 63, lives in Texas. The pair had not seen each other in person for several years, as Cary has cancer that requires lifelong treatment, which led Mary to believe she would not be able to adjust her treatment schedule to visit her. But secretly, Cary had reached out to Mary's daughter, Rachel, 29, to say she would like to surprise her mom for her 63rd birthday. Rachel had initially bonded the pair, as right after she was born, Cary became Rachel's nanny while the King family lived in the Baltimore area. Cary and Mary quickly became friends, and their families also came together for trips and celebrations of the holidays. When Rachel, 29, heard about Cary's plan to surprise her mom, she did everything possible to make it work. After Cary arrived in town in early December, she stayed with Rachel's brother before planning to head to a restaurant in Baltimore where Rachel and her mom would enjoy a birthday meal. On December 7, Rachel secretly started recording her mom in the restaurant as a "stranger" – Cary – approached and asked Mary if the seat next to her was taken. After Mary said no, it was not; it took a few seconds for everything to click.