Sutcliff won the annual Carnegie Medal from the Library Association, recognising the year's best children's book by a British subject.

[4] The title is from a remark by one of the characters, Eugenus the Physician, "We are the lantern bearers, my friend; for us to keep something burning, to carry what light we can forward into the darkness and the wind."

Rome is increasingly under threat from the barbarian hordes surrounding it on all sides and cannot afford to deal with the problems of a distant province.

Aquila is plotting his escape from the Saxon camp when he chances upon Flavia, who is now married to the man who abducted her and has a year-old child by him.

He stumbles upon a cheerful bee-keeping monk, Brother Ninnias, who lives by himself in a forest, the lone survivor of a Saxon raid upon his abbey.

Brother Ninnias advises him to take up his father Flavian's cause and offer his service to the Prince of Britain, Ambrosius Aurelianius.

In the years of skirmishes, uneasy truce and battles that follow, Ambrosius finally scores a decisive victory over the Saxons with the help of Artos (Arthur), his nephew, and Aquila.

With Brother Ninnias' help, he tends to the boy's injuries, hides him from British soldiers and sends him back to his mother with a message for her.

Aquila finally feels free and content even though he knows that the respite he and his people have found is only temporary and they cannot hold off the invaders from Britain forever.

The novel is set in Britain at the beginning of the Early Middle Ages when the once-dominant Roman empire was declining and tribes from the east began migrating into West Europe.

Arthur's supposed uncle, Ambrosius Aurelianus is seen as a remnant of the old Roman ways trying to defend his homeland against what seems to be an unstoppable invasion of foreign barbarians.

The book presents several other historical-mythical figures such as Hengist and Horsa, the Saxon chiefs who invade England and Vortigern, king of Britons.

The story juxtaposes several opposing points of view such as the resentment of the Romano-Britannic people who are being invaded by what they see as personifications of evil and darkness, and the desperate need of the continental tribes who face poor harvests and starvation in their own lands.