This book is a hoot! Time-travel romantic comedy, with literary allusions stirred in to taste. Most of the characters are stereotypes, but not badly-done, and I'm glad she's rationed the effusions of the mawkish Victorian maiden.
I could guess some but not all of the plot, and when I realised who the Victorian maiden was going to fall in love with—and why she had an aesthetic epiphany about the bishop's bird stump—I was hugging myself with delight as I saw the plot unreeling before me. In fact, like the ideal of a Golden Age mystery novel, it's very fair in putting out the clues, but for a lot of the time the reader is as bemused as the characters.
There are a succession of very Wodehouse-esque butlers who manage to be entertaining (in a dignified manner) throughout.
Animal-lovers will also enjoy this story; Willis has a light but accurate touch with both the dog and cat characters, and the reaction of the time-travelling protagonist to hearing his first purr is particularly nicely done.
There is only one thing that seriously annoys me about this book, which is the poor use of British English. It won't necessarily annoy the sort of Americans who aren't aficionados of British culture, but I'm not sure if they're the intended audience. Also, younger British people may well have watched enough American films and television that American turns of phrase come naturally to them. Any Brit of 30 or older, however, may be slightly jolted out of the willing-suspension-of-disbelief approximately once per page by the American usages (and let's face it, in this sort of fantasy-pastiche-comedy the w.s. of d. needs careful handling). I spent the first half of the book wondering if the protagonist was meant to be an American, then decided that the language was meant to be future-UK-English-more-influenced-by-American-than-at-present, and finally realised that she hadn't quite got it right when, in the Victorian setting, the peppery old Colonel, the credulous matron and the eccentric old Professor all use American turns of phrase. It's distracting because, in a time-travel story, anachronisms and social or verbal details are often part of the plot. She's done very well with a lot of it: verbal tics appropriate to the ex-military old gentleman, the Professor with a monomania, the poetic young gentleman and the mawkish maiden are all put in—which means it startles the reader when they all use 'gotten' and 'go [verb]' instead of 'go and [verb]'.
I don't think it's the business of the writer to Know Everything, of course, but it's sad to see a flaw like this getting in the way when a decent copy-editor could and should have fixed it—and God is in the details, as one of the characters remarks, and the writer should be aiming at affectionate-hommage rather than a theme-park version of British culture.
I'd give it five stars (not timeless-lit-classic but excellent-example-of-its-kind) if I wasn't so annoyed by the distracting language.