Best teen historical mystery books according to redditors

The House on Hound Hill?

https://www.amazon.com/House-Hound-Hill-Maggie-Prince/dp/0618331247

Mystery Box?

>What if Carolyn Keene and Franklin W. Dixon, the pseudonymous authors of the famous NancyDrew and HardyBoys series, were real people? That is the premise of this oddly contrived story, which is a combination of mystery, romance, and history. Initially set in 1918, and then moving to the 1920s, it takes both characters from their homes in the United States to Paris. Frank is led to France while tracking his missing army pilot brother, Joe. Carolyn travels there as a new high school graduate, ready to explore the world and leave her father, Carson, to his impending marriage. As Frank looks for clues to Joe's whereabouts, he becomes involved with a variety of literary figures, including Gertrude Stein, Alice B. Toklas, and Ernest Hemingway. As Carolyn hobnobs with literary notables such as F. Scott Fitzgerald and John Dos Passos, she unravels a mystery of her own. In the course of events, Carolyn and Frank meet and fall in love, and despite a brief estrangement, they marry, determined to write mystery stories for boys and girls as their life's work. Teens who have had a great affinity for the "NancyDrew" and/or "HardyBoys" books, and who are exceptionally familiar with the prominent writers of the 1920s, may find this an acceptable read. However, the sheer number of coincidental relationships and dealings with famous authors feels artificial, and the writing lacks spark despite some unexpected twists.–Diane P. Tuccillo, City of Mesa Library, AZ --Diane P. Tuccillo (Reviewed December 1, 2003) (School Library Journal, vol 49, issue 12, p157)