I read part of this book in high school, during the late 80s. I expect it was first published in late 70s or early 80s. I got it from my school library.

It was a young adult, horror novel involving time travel. It’s stuck in my head because I found it genuinely disturbing.

It was one of a series involving twins (white, boy and girl, about 15 years old, nice, popular, friendly kids) and their younger cousin (white, about 12, very intelligent, bookish, antisocial, bullied) from England. It was set whenever the book was written (late 70s to early 80s).

From what I recall, the kids went to visit family in the countryside, the cousin went too. The twins didn’t like their cousin, and it was mutual.

They discovered historical links between where they were staying and the Black Death era (1350-ish).

Then they began travelling back in time to London during the Black Death.

I can’t recall how they travelled back in time or how it was triggered. It may have been while sleeping. But it was some form of magic/mystical power the protagonists couldn’t control or understand - not technology.

This wasn’t a fun time travel romp. The twins didn’t want to go - it terrified them - but the cousin wanted to know what and why it was happening. The twins definitely showed signs of extreme stress - I vaguely recall they planned to run away due to it. There was something Lovecraftian about their mental deterioration.

The descriptions of London and the Black Death were scary.

I stopped reading the book after a graphic scene when the cousin travelled back and woke up alone in the arms of a woman who had died from the plague hours before. He was trapped, as the woman was in rigor mortis and had been holding him in her arms tightly, so he had to fight his way free. Everyone else in the room was dead.

There was at least one other book featuring these characters - I think it had a folk horror theme, and featured “mummers” (English morality plays from the Middle Ages, performed in villages and towns). I was going to read it next, but this one freaked me out, so I didn’t.

I know it wasn’t a “Goosebumps” book, or one from a similar franchise. And I’m 99% sure the writer was English.

I read part of this book in high school, when I was about 14, during the mid-to-late 80s. I expect it was first published in late 70s or early 80s. I got it from my school library. I read it in England. It was published in English. Was a thin paperback book - maybe 200 pages.

It was a young adult, horror novel involving time travel. It’s stuck in my head because I found it genuinely disturbing.

It was one of a series involving twins (white, boy and girl, about 15 years old, nice, popular, friendly kids) and their younger cousin (white, about 12, very intelligent, bookish, antisocial, bullied) from England. It was set whenever the book was written (late 70s to early 80s).

From what I recall, the kids went to visit family in the countryside, the cousin went too. The twins didn’t like their cousin, and it was mutual.

They discovered historical links between where they were staying and the Black Death era (1350-ish).

Then they began travelling back in time to London during the Black Death.

I can’t recall how they travelled back in time or how it was triggered. It may have been while sleeping. But it was some form of magic/mystical power the protagonists couldn’t control or understand - not technology.

This wasn’t a fun time travel romp. The twins didn’t want to go - it terrified them - but the cousin wanted to know what and why it was happening. The twins definitely showed signs of extreme stress - I vaguely recall they planned to run away due to it. There was something Lovecraftian about their mental deterioration.

The descriptions of London and the Black Death were scary.

I stopped reading the book after a graphic scene when the cousin travelled back and woke up alone in the arms of a woman who had died from the plague hours before. He was trapped, as the woman was in rigor mortis and had been holding him in her arms tightly, so he had to fight his way free. Everyone else in the room was dead.

There was at least one other book featuring these characters - I think it had a folk horror theme, and featured “mummers” (English morality plays from the Middle Ages, performed in villages and towns). I was going to read it next, but this one freaked me out, so I didn’t.

I know it wasn’t a “Goosebumps” book, or one from a similar franchise. And I’m 99% sure the writer was English.

I read part of this book in high school, during the late 80s. I expect it was first published in late 70s or early 80s. I got it from my school library.

It was a young adult, horror novel involving time travel. It’s stuck in my head because I found it genuinely disturbing.

It was one of a series involving twins (white, boy and girl, about 15 years old, nice, popular, friendly kids) and their younger cousin (white, about 12, very intelligent, bookish, antisocial, bullied) from England. It was set whenever the book was written (late 70s to early 80s).

From what I recall, the kids went to visit family in the countryside, the cousin weeny too. The twins didn’t like their cousin, and it was mutual.

They discovered historical links between where they were staying and the Black Death era (1350-ish).

Then they began travelling back in time to London during the Black Death.

I can’t recall how they travelled back in time or how it was triggered. It may have been while sleeping. But it was some form of magic/mystical power the protagonists couldn’t control or understand - not technology.

This wasn’t a fun time travel romp. The twins didn’t want to go - it terrified them - but the cousin wanted to know what and why why it was happening and why them. The twins definitely showed signs of extreme stress - I vaguely recall they planned to run away due to it. There was something Lovecraftian about their mental deterioration.

The descriptions of London and the Black Death were scary.

I stopped reading the book after a graphic scene when the cousin travelled back and woke up alone in the arms of a woman who had died from the plague hours before. He was trapped, as the woman was in rigor mortis and had been holding his finger tightly, so he had to fight his way free. Everyone else in the room was dead.

There was at least one other book featuring these characters - I think it had a folk horror theme, and featured “mummers” (English morality plays from the Middle Ages, performed in villages and towns). I was going to read it next, but this one freaked me out, so I didn’t.

I read part of this book in high school, during the late 80s. I expect it was first published in late 70s or early 80s. I got it from my school library.

It was a young adult, horror novel involving time travel. It’s stuck in my head because I found it genuinely disturbing.

It was one of a series involving twins (white, boy and girl, about 15 years old, nice, popular, friendly kids) and their younger cousin (white, about 12, very intelligent, bookish, antisocial, bullied) from England. It was set whenever the book was written (late 70s to early 80s).

From what I recall, the kids went to visit family in the countryside, the cousin went too. The twins didn’t like their cousin, and it was mutual.

They discovered historical links between where they were staying and the Black Death era (1350-ish).

Then they began travelling back in time to London during the Black Death.

I can’t recall how they travelled back in time or how it was triggered. It may have been while sleeping. But it was some form of magic/mystical power the protagonists couldn’t control or understand - not technology.

This wasn’t a fun time travel romp. The twins didn’t want to go - it terrified them - but the cousin wanted to know what and why it was happening. The twins definitely showed signs of extreme stress - I vaguely recall they planned to run away due to it. There was something Lovecraftian about their mental deterioration.

The descriptions of London and the Black Death were scary.

I stopped reading the book after a graphic scene when the cousin travelled back and woke up alone in the arms of a woman who had died from the plague hours before. He was trapped, as the woman was in rigor mortis and had been holding him in her arms tightly, so he had to fight his way free. Everyone else in the room was dead.

There was at least one other book featuring these characters - I think it had a folk horror theme, and featured “mummers” (English morality plays from the Middle Ages, performed in villages and towns). I was going to read it next, but this one freaked me out, so I didn’t.

I know it wasn’t a “Goosebumps” book, or one from a similar franchise. And I’m 99% sure the writer was English.