"Mirror Dance (Miles Vorkosigan Adventures)" by Lois McMaster Bujold
https://www.amazon.com/Mirror-Dance-Miles-Vorkosigan-Adventures/dp/0671876465/

Book number eleven (in chronological order) of an eighteen book space
opera series. However, some people call this a military science fiction
series. There are several other books and short stories in the
Vorkosigan Universe. This series won the Hugo and Nebula awards for
best series in 2017. Also, several of the individual books in the
series have either won awards or been nominated for awards. This book
won the 1995 Hugo award for best novel, back when Hugo awards meant
something. I have read this book at least twice. I reread the well
printed and well bound used MMPB published by Baen in 1995 that I just
rebought on Amazon, the book is not available new in any printed format.
I have rebought the rest of the books in the series in various
formats, mostly MMPB.

Lord Mark Vorkosigan has managed to deceive the Dendarii Free Mercenary
Fleet into believing that he is Admiral Naismith and has set into motion
a series of events that are breathtaking. As Lord Mark took one of the
warships to Jackson's Whole, the real Admiral Naismith arrived at the
fleet and then took off trying to catch up. And gets there just in time
to take a needle grenade in the chest.

Vorkosigan Saga (Chronological) by Lois McMaster Bujold
https://www.goodreads.com/series/98254-vorkosigan-saga-chronological
1. Dreamweaver's Dilemma
2. Falling Free
3. Shards of Honour
4. Barrayar
5. The Warrior's Apprentice
6. The Borders of Infinity (The Mountains of Mourning, etc)
7. The Vor Game
8. Cetaganda
9. Ethan Of Athos
10. Brothers in Arms
11. Mirror Dance
12. Memory
13. Komarr
14. A Civil Campaign
15. Diplomatic Immunity
16. Captain Vorpatril's Alliance
17. CryoBurn
18. Gentleman Jole and the Red Queen

My rating: 6 out of 5 stars (yup, six stars)
Amazon rating: 4.7 out of 5 stars (320 reviews)

Lynn