The Notorious Benedict Arnold: A True Story of Adventure, Heroism and Treachery, written by Steven Sheinkin and published in 2010, is a biography for young readers about one of America's notable war heroes who was also her most famous traitor—Benedict Arnold. How this startling reversal came about is traced in the book, which is rigorously researched yet presented in the manner of an adventure novel. Sheinkin confronts the moral ambiguities that lie at the heart of Arnold. The book is structured in 45 short, titled chapters and includes maps, a bibliography, a portrait of Arnold, an index, and an interview with the author.

Benedict Arnold is born in Norwich, Connecticut, in 1741 to a successful merchant who after a reversal of fortune falls prey to alcoholism. As a boy, Arnold is rebellious, a “thrill seeker, a natural athlete, a born show-off” (7). The family's financial loss compels Arnold to apprentice to an apothecary for seven years instead of going to college. He eventually establishes himself as a pharmacist and bookseller in New Haven. In 1767 he marries Margaret Mansfield, who will bear him three sons before dying of unknown causes in 1775.

When the American Revolution erupts in March 1775, Arnold joins and is elected leader of the Connecticut militia. Alongside Ethan Allen, he leads the successful attack on the British-held Fort Ticonderoga in New York, after which General George Washington appoints him to lead an expedition to conquer the city of Quebec. Following a grueling march with 700 men across the Maine wilderness into Canada, Arnold leads an attack on well-fortified Quebec in which he is severely wounded.

Now promoted to the rank of brigadier general, Arnold stages a successful assault on a British navy fleet on Valcour Island on Lake Champlain. He returns a hero but some in the military distrust him for his rash, hot-tempered nature, giving rise to rumors that damage his reputation. When the time comes for Congress to appoint new generals, Arnold is passed over in favor of his juniors. Only the intervention of George Washington prevents Arnold from resigning in disgust. Arnold's next victory is at the Battle of Saratoga, which causes him to be restored to his proper rank. 

After the British discontinue their occupation of Philadelphia, Arnold is given command as governor of the city. There he lives extravagantly—thanks to having participated in legally questionable trade dealings—and marries a new wife, Peggy Shippen, a young woman of Loyalist sympathies. Pennsylvania's supreme executive council apprehends him for his trade dealings and refers the charge to Congress, which arranges for a court-martial. He is cleared of the most serious charges and receives a sentence only a reprimand from General Washington. 

At this point Arnold decides secretly to defect to the British side in order to put an end to the war and achieve personal glory. He first obtains from General Washington the command of West Point, a fort that is vital in protecting America from the British. From there he negotiates with Major John André, an important British army official, to surrender West Point to the British. Arnold's plot is exposed when André is arrested en route to New York by four militiamen; André is then executed by hanging. 

Having officially switched sides in the war, Arnold now leads military raids on Richmond, Virginia and New London, Connecticut, not far from his home town, where he is widely reviled. After Lord Cornwallis's surrender at Yorktown ending the war, Arnold and his family leave America to settle in London. Arnold fails to obtain positions with the British military or government, as many people suspect the motives for his switch of allegiance. 

Arnold tries various business ventures, including land speculation and trade with the West Indies, but all without success. A decline of his health leads to his death in 1801 at the age of 60. Peggy Arnold dies three years later and is buried beside her husband. 

Sheinkin weaves into the narrative episodes from the life of John André, a man whose path eventually crosses with Arnold's to fatal consequences for both men. We first meet André as a British soldier patrolling one of the British-held forts in Canada. The Americans capture him as a prisoner of war, and he eventually ends up in New York where he makes a meteoric ascent in the British military. This leads to his being chosen to facilitate Arnold's crossing over to the British side. 

The Notorious Benedict Arnold limns the portrait of a complex and conflicted man: a brave and brilliant soldier, but one in whom egotism, ambition, and expediency—fueled by increasing bitterness and resentment—finally outweighed loyalty to the cause of American independence. Sheinkin's book won a 2012 award for Excellence in Nonfiction for Young Adults.