In the novel The Hollow, Terence "Terry" Christow is John and Gerda's twelve-year-old son. He is perceptive, observant, analytical, curious and lonely. He is highly interested in chemistry and always making statements about chemical tests and reactions. At one point he broke the cona coffee machine because he wanted to try to make ammonia. In some ways he takes after his father.
His father thought of him as someone who might actually been interested in listening to him prattle on about his interest in Ridgeway's disease. As for Terence trying to make ammonia, John Christow thought of it as interesting. The adults had lied to him but he found out that it was murder. As Gerda Christow realised, it is no point trying to hide anything from Terence. His detached scientific mind had a curiosity which must be satisfied. Terence was quietly and in his own way affected by his father's death, more than he would admit and more than others noticed. He had planned to make nitroglycerine with his friend Nicholson Minor but after his father died, he did not feel like doing science experiments anymore, a fact that seemed to shock even himself.