British comedy series

A distraught man in coat and tie grips the guardrail at a remote cliff overlooking the Pacific. At a boys' high school in toney Rancho Palos Verdes, Mr. Radford teaches classics. His best student is the earnest Andrew. Late one evening, Andrew stops by Mr. Radford's office; Andrew's been the only student to do well on a recent exam. They chat, and something happens that brings a sleepless night to Mr. Radford. The next day, Andrew misses Mr. Radford's class, and after, Mr. Radford is aghast to see Andrew and Andrew's father waiting outside the principal's office. What's the teacher's fear, and what will he do about it?