Some minor spoilers below, mostly from the first few chapters of the book.
The Companions was quite a surprise. I left R.A. Salvadore's story after finishing the Paths of Darkness's final book, the Sea of Swords. Wulfgar, now with an adopted child, had finally come to grips with his traumatic past and had taken steps to stride into his future. He'd been reunited with the the Companions and found his great warhammer, while Drizzt and Cattie-brie had fallen in love. I missed what happened next: the deaths of the Companions, and Drizzt's adventures with his new associates--those who did not share his morals and ideals.
Now, as The Companions begins, Bruenor, Cattie-Brie, Regis, and Wulfgar find themselves in a kind of strange pocket-plane created by Mielikki, a goddess of nature and the patron of Drizzt. They are faced with a choice: do they continue on to their just reward, or do they instead accept a gift from Mielikki and be reincarnated on Toril, tasked to help Drizzt in his time of need. What follows is the story of how those who choose to return are born and live through their early years once again. It explores an interesting question: what would it be like to live your life again, having the memories, knowledge, and cognitive function of your prior life?
Each of the characters' new life story is faced with its own challenges, and in these we see each character grow and develop in leaps and bounds. Their stories dominate this book--in truth, Drizzt gets far less screen time than the cover might suggest--and each has an eventful childhood and early adolescence. By the end of the story, several are quite simply not who they were when the tale began. Some of the individual plot-lines work better than others, but overall it is an enjoyable read...and a book that has me eagerly awaiting the next in the series.
A few specific comments (major spoilers follow!!)