Alison
Alison asked Jodi Taylor:

This question contains spoilers… (view spoiler)

Jodi Taylor Hi - sorry for the delay. I've had one of those bug things. Not THE bug, thank goodness, but the sort that stops you putting two coherent thoughts together. Anyway - back to Markham. The reason the ghost didn't appear sooner is because the idiot author didn't think of it until that point. And yes, they did interfere a little bit with History simply by being there, but that happens to a greater or lesser extent on every jump. If you think about it, just by standing in a particular spot, you prevent someone else standing on that particular spot. Which means that someone else is in the wrong place and the whole thing has a kind of knock on effect.
They REALLY interfere with History in The Ordeal of the Haunted Room (out at Christmas). Even Dr Bairstow expresses surprise that History has allowed them to live.
Thanks for your question. Regards, Jodi.

About Goodreads Q&A

Ask and answer questions about books!

You can pose questions to the Goodreads community with Reader Q&A, or ask your favorite author a question with Ask the Author.

See Featured Authors Answering Questions

Learn more