The Last Hours is a trilogy written by Cassandra Clare and is the sequel series to The Infernal Devices. It is the fourth series published in The Shadowhunter Chronicles, but is the second chronologically. Its export rights were acquired by Walker Books.
- Chain of Gold and Chain of Iron are both narrated by Finty Williams.
The Shadowhunters enter the Edwardian era in The Last Hours. Will Herondale is head of the London Institute, where he lives with his wife Tessa. But now it's their children, James and Lucie, who take center stage, alongside their parabatai, Matthew Fairchild and Cordelia Carstairs. Begin their adventures in Chain of Gold.
Set in Edwardian London and fin de siècle Paris 1903, right around the time the Victorian era tips over into the Edwardian era, The Last Hours will deal with Will and Tessa's children (James and Lucie), Jem Carstairs' cousins (Alastair and Cordelia), Charlotte and Henry's children (Charles and Matthew), Tatiana Blackthorn's children (Jesse and Grace), Cecily and Gabriel's (Anna, Christopher, and Alexander), and Gideon and Sophie's children (Thomas, as well as Barbara and Eugenia), and many more.
The story will be told in James and Lucie's point of views, among others. The main characters, at 16-17 years old, will be James, Lucie, Cordelia, Alastair, Matthew, Charles, Grace, Jesse, and Christopher, who are the children of characters from The Infernal Devices. Most of the characters from The Infernal Devices, now aged and older, will make appearances.
The Last Hours will deal quite a bit with Clave politics, as well as their attitude and view about certain issues such as homosexuality, and moves back and forth between London, Paris, Cornwall, and Idris. Iron Sisters are also expected to become important in the series.
- While certain possible relationship outcomes have already been revealed in a family tree previously released with Clockwork Princess, the family tree is said to be misleading, consisting of information thought true by whoever wrote it; it will be made clear in the series.
- Will and Tessa will have POVs in the series.
- The Pandemonium Club may make a reappearance in this series.
- Woolsey Scott and Camille Belcourt are set to return for this series.
- How Bridget Daly became very long-lived will be told in the series.
- The villain that will be dealt with in this series is different from those in the other Shadowhunters books, "almost a force rather than one specific person or thing."
- A plague pit may be featured in this series.
- Cortana will play a very important role. 
- There will be several complicated love triangles in this series.
- The story is meant to connect in some way with The Wicked Powers series specifically; in addition to general connections with The Mortal Instruments and The Dark Artifices series.
- There will be more Princes of Hell appearing in the trilogy other than Belial.
- Below are teased snippets that may appear in future books or may have been deleted from released books. For more, either go to the individual book page(s) above or check the unidentified snippets page.
James could see his mother moving like an anxious pale star among the guests in her lilac dress, greeting each of them warmly, welcoming them to her home. She had not glamoured herself to look her husband's age for the evening, and she appeared enormously young, though her hair was done up like a gracious older woman's, not a girl's. When Will materialized out of the crowd and came to put his arm around Tessa, smiling down at her, the gray at his temples flashed like silver. James looked away; he loved his parents for being extraordinary, but sometimes he also hated them for the same thing.
Anna raised her eyebrow at James as he turned away, but James ignored it. Anna had been raising her eyebrows at him all his life.
James' heart lurched in his chest. "We were childhood friends."
"But is it wise to prove James isn't a lunatic?" said Matthew.
"Matthew told me what happened at the park," Will muttered in a voice no one but James could hear. James shot a betrayed look at Matthew, who shrugged and gave him a half-smile. Matthew could be relied on to tattle on James if he thought it was for his own good. "Thank the Angel for Matthew and Thomas and Christopher." He touched James' face. "I regret ever having said that your generation was wasting its time with parties and boating and dancing. All I wish for you is to be able to amuse yourself in a pointless fashion during peace and never, ever be in danger."
"That was vile, what you made me do, and vile that you made me do it."
Does love mean anything to you, she said. Or is it just something people give you easily, the way you give toys to a child?
The house has all fallen down into ruins, he said.
We could get married, she said
"Can no one else see you?"
Be careful what you say to me, Grace told him. There is nothing I cannot make you do.
"Stop!" James cried. He felt as if he were drowning. He had always been shy...
Make a wish, Jamie
Cordelia blinked, bewildered. "James?"
"I suffered every thorn for you," he said. "I would again."
Not tie him to the bed, Cordelia thought. Not cut his beautiful hair. She loved his hair: it was black like his father's, black as night, dark as a place you could tell secrets in.
"You lied to me," she said.
The moonlight softened the harsh gold of James' eyes to a dark umber. How changed would his life have been if his eyes had not been a sign of his difference?
"You carry my life in those careless hands"
"Delicate boys must be protected," said Anna.
"To the last hour."
Death is not the end
"Hold my hand, James," she said.
"Preferably not boys," said Anna, without looking up. "Then I have to pretend to be interested."
"That's because you’re drunk," said James. They were both sprawled at the same round table in an upper room of the Devil Tavern on Fleet Street.
Barbara patted Thomas, as if his brawny arm was a small boy’s head. "I was merely anxious about you, Tommy. Surely you are not vexed."
Thomas’s brows were drawn sharply together, making his amiable countenance dark for the briefest interval. Then he sighed, drew his sister toward him in the circle of his arm, and stooped to press a kiss upon her brow.
"No, Babs," he said. "Of course I am not vexed. Can you spare your brother a dance, though I know Oliver will be loath to part with you? I will take care not to be clumsy."
"What if Cordelia has changed her mind, and says she will not have a minx like you?"
"She would never!" Lucie was outraged.
"No," Will agreed. "She would not. As far as I am concerned, you shall perform the ceremony as soon as you please. All I want is for you and Cordelia to live a long and happy life, and never be parted."
"Christopher," said Thomas. "Would you take James away immediately and show him an interesting scientific experiment?"
Christopher frowned. "Which one?"
"Any one at all!" said Thomas. "I will escort the ladies home."
Christopher’s brow cleared. "Ah, I understand perfectly. This is what Matthew said we were to do, about not letting James out of our sight and above all else keeping him away from..."
He trailed off, gazing at Grace with distant alarm.
Apprehension stole across Thomas's face. "Lucie, you must not challenge Grace to a duel."
"We shall see where the night takes us," Lucie declared.
"Oh good," said Thomas. "I see you intend to Herondale to the fullest."
He took a deep breath, and crossed the floor of blades and constellations to the other boy’s side. He stood at the foot of the stairs, looking down.
“But of course,” he said, very softly, “your sentiments are reciprocated.”
He stooped over him, tilting his chin up. Their lips met. The other boy made a soft sound, almost like surrender, stretching under his body. He slid an arm around his neck and pulled him down onto the stairs.
“Disgraceful,” said Mrs Bridgestock. “I know your face. You are that Persian boy. Are you not ashamed to be running around corrupting nice young people? I suppose you are only following your father’s example, but considering what happened to him, you should really know better.”
Cordelia wished to rush to her brother’s defense, but she did not dare move.
Alastair bared his teeth at Mrs Bridgestock. “I should, shouldn’t I?”
“I respect a heartbreaker,” said Anna. “People are better off without hearts anyway. But you don’t leave people better off. You’re not a heartbreaker, Grace Blackthorn. You’re a life destroyer.”
- The series and book titles were taken from the Charles Dickens' classic novel Great Expectations, of which the series is a loose form of retelling (with there being parallels among characters: James like Pip and Grace as Estella (with many readers assuming that Cordelia is like Biddy in the situation), Matthew like Herbert, and Tatiana as Miss Havisham).
- According to Cassandra Clare: "The books will interconnect with The Dark Artifices trilogy as two separate trilogies that are also the stories of the Blackthorns, Herondales and Carstairs, much like The Mortal Instruments and The Infernal Devices interconnected despite taking place in different time periods and locations." In line with this, the series was originally set to be released alternately with The Dark Artifices, before Chain of Gold was delayed until after The Dark Artifices finale.
- Cassandra Clare released ten short stories (vignettes) revolving around the characters from The Last Hours, including Matthew Fairchild, Thomas Lightwood, James Herondale, Lucie Herondale, Cordelia Carstairs, Anna Lightwood, and more. They were released online to be read for free each month leading up to the release of Chain of Gold.
- "I think after you read TLH [...] you’ll know why the Blackthorns don’t see ghosts." Cassandra Clare on Tumblr
- "Welcome to Pandemonium" - Cassandra Clare on Pinterest
- Woolsey Scott pin — Cassandra Clare on Pinterest
- TLH questions — Cassandra Clare on Tumblr
- "Very likely!" Cassandra Clare on Twitter
- Camille pin 1 — Cassandra Clare on Pinterest
- Camille pin 2 — Cassandra Clare on Pinterest
- Camille pin 3 — Cassandra Clare on Pinterest
- Camille pin 4 — Cassandra Clare on Pinterest
- Camille pin 5 — Cassandra Clare on Pinterest
- Camille pin 6 — Cassandra Clare on Pinterest
- "You will find out how she became not immortal but very long-lived in TLH -" Cassandra Clare on Tumblr
- "You’ll have to wait for TLH for that!" Cassandra Clare on her Tumblr
- Cassandra Clare at BookCon 2018
- Cassandra Clare on Tumblr
- "Several!" Cassandra Clare on Tumblr
- "Sure, there are others." Cassandra Clare on Tumblr
- "TLH has bearing on TMI, TDA and TWP. (TLH and TWP are especially connected.)" Cassandra Clare in a comment on Instagram
- "Yep [there will be more Princes of Hell appearing in TLH other than Belial]!" Cassandra Clare on Tumblr
- "TDA will be alternate with TLH as TMI and TID? Say yes, Cassie, pretty please." "yes."
- Tentative book release schedule in 2017 — Cassandra Clare on Tumblr
- Cassandra Clare Newsletter from September 2017