Glenconner barely disguises herself in her detective. Lady Veronica Blake, known affectionately as Lady Vee, owns the island of Mustique with her husband and was a Lady in Waiting to Princess Margaret.

Murder on Mustique is set in 2002, the year Princess Margaret died. Lady Vee, at her home in Norfolk, is still mourning the princess, remembering the royal tours.

"The glitter of flashbulbs that surrounded her, flattering at first, then cruel in the months before her death", and how the princess enjoyed the freedom she found on Mustique.

However, all is not well on Mustique. Amanda Fortini, daughter of an Italian-American coffee magnate has gone missing.

Amanda's friend Lily Calder, suspicious and scared, calls her godmother, Lady Vee.

Remembering that her parents named her after a particularly stalwart heroine in a novel by HGWells, Lady Vee catches the next flight to Mustique.

The island's only policeman, Oxford graduate Detective Sergeant Solomon Nile, believes Amanda should be easily found on such a small island, especially as most of the wealthy villa owners have left with the approach of tropical storm, Cristobal.

But Amanda has been murdered and when her rich boyfriend disappears, Nile and Lady Vee co-operate to track down the killer.

Murder on Mustique is entertaining, but it's not great literature, rather a combination of TV's Murder in Paradise and in places, Ian Fleming's James Bond.

SJ Bennett moves further up the aristocratic ladder with her detective in The Windsor Knot (Zaffre, $29.99), the first in what Bennett describes as "a mystery series with a very special detective. The Queen solves crimes."

Bennett says the idea came to her after watching an episode of The Crown, in which the Queen picks up a model soldier from a battlefield and puts him back in the wrong place.

She thought, "She'd never do that. She would have recognised the battle . . . I know this because my father, who met her several times during his career in the army, has always been impressed by her knowledge of military history."

Bennett is convinced the Queen is an expert in many fields and is too often underestimated as "a little old lady in a hat".

Therefore, she thought, "how interesting it must be to be looking out, when everybody else is looking at you and how much you must spot that other people don't see. As soon as I had that idea, I thought 'Detective', she'd be brilliant".

Bennett's Queen Elizabeth has a remarkable memory, a fine eye for detail, is a shrewd judge of character and enjoys the occasional glass of gin. She naturally "glows" and "glitters" and is know affectionately by all her staff as "the Boss".

She loves Windsor Castle, not Buckingham Palace, "which was like living in a gilded office block on a roundabout".

She believes that "if the revolution ever came . . . this was where she would ask to retire".

The Windsor Knot is set in 2016, the year of the Queen's 90th birthday celebrations. The Easter Court is at Windsor, where the Queen can entertain in a more informal style, inviting a small group to "dine and sleep".

But the morning after a party held a week after Easter, a young, promising, Russian pianist Maksim Brodsky is found dead in his room in compromising circumstances.

The Queen had been impressed by Brodsky, "he was quite magnificent . . . and he was so good looking".

"He had danced the foxtrot with her and "managed to make one feel like Ginger Rogers".

Even though the police quickly establish that Brodsky has been murdered, the combined efforts of MI5 and the Metropolitan police can get no further than suggesting it's an assassination ordered by Putin.

The Queen begins her own investigation, enlisting the help of her new Assistant Private Secretary Rozie Oshodi to interview the guests at the "dine and sleep" and contact ex-policemen who have obviously helped her before.

One of Rozie's predecessors tells her, "the Queen solves mysteries. She solved the first one when she was twelve or thirteen . . . on her own.

"She sees things other people don't see . . . she's got an eagle eye, a nose for bullshit and a fabulous memory."

The Windsor Knot is witty and engrossing, mainly because the voice of Bennett's Queen Elizabeth is so convincing, it seems authentic.

Bennett's Queen is someone we would all like to meet.