
1970 Coronet edition
9th Matt Helm thriller
1966 Gold Medal paperback original in the US

1970 Coronet edition
9th Matt Helm thriller
1966 Gold Medal paperback original in the US

first published in 1920 by Ward as The Daffodil Mystery. it was published the following year by Small Maynard in Boston with this title
cover art by Richard Lyon repurposed from G-Men Magazine, May 1938
