It is part of the series that began with The Thirty-Nine Steps, coming between the fourth novel, The Three Hostages, and the final novel, The Island of Sheep. Unlike the other novels in the series, it does not star Richard Hannay — he narrates the first few chapters, then bows out and leaves the adventure in the hands of his supporting cast. It does however feature most of the series' other recurring characters, and introduces two new characters who return in The Island of Sheep.
Nearly every member of the recurring cast except Sir Richard and Lady Hannay (who for once successfully protest that they're retired and have a family to look after, and don't appear after the first few chapters) get involved in stopping a criminal mastermind plotting world domination in South America. The lead role is shared between Sandy Arbuthnot (introduced in Greenmantle) and Archie Roylance (introduced in Mr. Standfast).
The Courts of the Morning contains examples of:
- Age-Gap Romance: Sandy Arbuthnot and Barbara Dasent meet and fall in love when he's in his early forties, and she's twenty-four. They don't start a relationship until the last page of the novel, with the age gap being one of the factors that make both of them reluctant to admit their feelings. In the sequel, they're happily married.
- Attempted Rape: The bad guys take Janet Roylance hostage after things start going against them. She's kept in a locked room at nights for her own protection, because the mooks are really not nice people and some of them have designs on her, and their leaders no longer have enough influence to keep them in line by word alone. One of the mooks manages to gain access to her room, but fortunately the heroes arrive to break her out in the nick of time.
- Banana Republic: The setting of the novel is Olifa, a South American republic where the President and cabinet are in the pocket of a multinational mining corporation whose copper exports are the mainstay of its prosperity. A revolution by Oliferans who want their country's destiny back in Oliferan hands takes up a large part of the plot.
- Bedouin Rescue Service: Played with. Archie Roylance and Geordie Hamilton are stranded in the highlands of Olifa after a plane crash and are at the ends of their endurance when they're found by a group of native warriors. It turns out not to be an entirely chance meeting: the warriors are working with Luis de Marzaniga, another of the heroes who had been previously established to have a rapport with the local tribes, and were in the area looking for the same thing Archie and Geordie came to the highlands looking for.
- Cut Phone Lines: Used several times, by both the heroes and the villains.
- Died in Your Arms Tonight: At the end, the reformed Castor is murdered, and dies held in the arms of the woman he loves.
- Faking the Dead:
- Early in the book, it's reported that spymaster John S. Blenkiron has died. Later, it turns out he only faked his death because the Big Bad had started to suspect he was on to him.
- Later in the book, Sandy fakes the death of his cover identity once it's outlived its usefulness, so that he can move on to the next stage of the operation without anyone wondering where he's disappeared to.
- Fantastic Drug: Part of the Big Bad's scheme depends on a drug called "asturas", derived from a rare plant found in the mountains of Olifa, which has exactly the properties required to make the plot work.
- Fictional Counterpart: Olifa, the fictional South American country, is based on Peru.
- Intro-Only Point of View: The Courts of the Morning begins with Hannay narrating in first person as usual, for three chapters of him being approached to come out of retirement, discussing things with Sandy, Archie and Janet, and finally deciding definitively to stay home and not get involved. From chapter 4 the narration switches to third person and starts following Archie and Janet instead, and Hannay is not seen again until the beginning of the next novel.
- I Will Only Slow You Down: When Archie Roylance and Geordie Hamilton are stranded halfway up a mountain and Geordie is seriously injured, Geordie tries to tell Archie to leave him behind. Archie of course refuses, and they both survive.
- Master of Disguise: Sandy Arbuthnot. There's a scene where Archie Roylance meets him in disguise without having the slightest clue that it's him.
- No Celebrities Were Harmed: In The Courts of the Morning, Sandy Arbuthnot's physical appearance is very similar to that of T. E. Lawrence (which it had not been in earlier novels like Greenmantle). Lawrence was a friend of Buchan's, although they only met after the First World War.
- Once per Episode: Every previous novel with Sandy Arbuthnot in (and the subsequent one) has a bit where Sandy goes off on his own to find out what he can about the villains, disappears without leaving any message, and then an apparent antagonist turns out to be Sandy in a disguise he's adopted to infiltrate the villain's organisation. This novel, where Sandy is the main character instead of Hannay, still does it, but gets the whole business out of the way within the first ten chapters.
- Redemption Equals Death: The heroes go to a lot of effort to help the Diabolical Mastermind to a HeelFace Turn, figuring that he's not positively evil, just twisted by a cynical and friendless privileged upbringing, and is capable of being as great a force for good as he is for evil. It works, and as the book reaches its close, he's looking forward to a new future and the good he can do for the world and his new friends — and then in the last chapter he's murdered by a vengeful former henchman who escaped the round-up of his old criminal organization.
- Refusal of the Second Call: Hannay once again declines a request to come out of retirement, and this time for once it sticks, leaving the heroics to his younger friend Archie Roylance.
- Rope Bridge: There's a chase through the South American jungle that ends when the heroes get across a rope bridge and cut it behind them, sending their pursuers plummeting.
- The Spymaster: John Blenkiron.
- Stating the Simple Solution: In an unusual variation, it's the Diabolical Mastermind who points out the simple solution to the heroes. The heroes capture the Diabolical Mastermind about a third of the way in, as the first step of a complicated scheme that takes the rest of the novel to play out. When he starts to get an idea of what they're planning, he points out that it would be simpler and safer for them just to shoot him now. They reply that getting him out of the way isn't the only thing they're trying to achieve, and because they're the heroes their complicated scheme does end up achieving nearly everything they wanted.
- Twice Shy: Barbara admits to a friend that she loves Sandy but believes she doesn't have a chance with him, and Sandy admits to another friend that he loves Barbara but believes he doesn't have a chance with her. The novel ends just as the latter friend nudges the two of them together. In the sequel, they're married.
- Wacky Americans Have Wacky Names: John S. Blenkiron. (The S stands for "Scantlebury".)
- Year X: The opening sentence gives the date as "the August of 192-".