Are You a Mystery Maven? The Gervase Fen Quiz

I admit it, I do have a favorite Allingham (Hide My Eyes), but with Edmund Crispin, it's more a case of when I'm not near the book I love, I love the book I'm near. (A very bright gold star to the first reader to ID that somewhat fractured lyric!). I mean, I love them all. The following teasers, then, range across the entire Gervase Fen oeuvre:

1. Whose destiny is it to save the world from Martian attack? 2. With the Nazis vanquished, what opera may the Oxford singers at last perform again? 3. In which book is the vacationing Professor Fen repeatedly distracted by a narcoleptic horse? 4. Fen's political ambitions are hampered by the appearance of an underdressed gentleman who believes himself to be a certain American president. Which one? 5. What well known English writer has declared Crispin's The Moving Toyshop one of the five best mystery novels of all time? (Extra credit for naming the newspaper in which this declaration appeared.)

Last week's quiz, now with an answer!