I decided to sample a few other alternate Holmes novels while I am between series rereads, and Carole Nelson Douglas's run of eight books, published between 1990 and 2004, that feature Irene Adler as the protagonist, sounded promising. The first one is astonishingly busy, but it ends quite satisfactorily and has me looking forward to the others in the line.
The book covers the first several years of Penelope "Nell" Huxleigh's association with Adler, a rising star of the opera and a trusted, discreet agent who the rich, the powerful, and the literary-minded can call upon for delicate investigations. Adler and Huxleigh are shown to join forces at the same time that Holmes and Watson meet in A Study in Scarlet, and their adventures progress over a period of a few years, climaxing with the famous events from the classic Scandal in Bohemia, here shown from Adler's perspective.
The slow, deliberate pace of the book, along with the way it covers several years, took a little getting used to, but I enjoyed the whole, sprawling epic. It takes in cameos by the likes of Oscar Wilde, office politics in a barrister's chambers, cross-dressing, and a thrilling escape by train across Europe, setting the stage for one of the most well-remembered encounters of Sherlock Holmes' career. It left me looking forward to what Douglas had planned for her characters next. Recommended.