During an Enclave meeting discussing how to deal with Alexei de Quincey, Frederick scoffed at the idea that de Quincey was building a clockwork army. When they were told of how their plan involved using one of Henry Branwell's unstable inventions, the Phosphor, he was extremely wary and reminded them of the last time they agreed to it. Nonetheless, the raid of the Enclave on de Quincey's manor went forward as planned.
- Though he was not featured in the book, Frederick was among the many casualties of Mortmain's automaton attack on the Council meeting in December 1878 in Clockwork Princess. After his death, the Ashdown name was considered inactive and was chosen by Sophie Collins upon her Ascension. The name was also later reused, after it again became inactive when Sophie became a Lightwood.