In the early morning of November 29, 2019, surveillance cameras at the headquarters of MI6, Britain’s spy agency, captured video of a young man pacing back and forth on a high balcony of Riverwalk, a luxury tower on the bank of the river Thames. At 2:24 a.m., he jumped into the river. In a quiet London neighborhood several miles away, Rachelle Brettler was worried about her son. Zac had told her that he had gone to stay with a friend, but then he did not come home. Days later, a police car pulled up, and two officers relayed the dreadful news: her son was dead. In their unbearable grief, Rachelle and her husband, Matthew, struggled to understand what had happened to Zac. He had his troubles, but in no way did he seem suicidal. As they would soon discover, however, there was a lot they did not know about their son.