THEY revived a medieval tradition and launched a new one in the process, but 42 years later their whereabouts is a mystery in its own right.
The Lincoln Mystery Plays were written by priests in the 15th and 16th centuries and performed as a way to tell stories from the Bible.
But they became so popular, they moved outside the church and became the responsibility of crafts and trades guilds.
After hundreds of years, in 1969, the mystery plays came back to Lincoln with a cast including Alison Steadman, now of Gavin and Stacey fame, Philip Hedley and Martin Duncan.
The performance took place inside Lincoln Cathedral and also including actors from the city's Lincoln Theatre Royal and about 100 local schoolchildren.
In October, the Lincoln Mystery Plays Theatre Company is holding a fundraising gala and wants members of the original 1969 cast to be involved.
Geoff Readman, chairman of the Lincoln Mystery Plays Trust, said it was important to keep the memory of the first revival alive.
He said: "My understanding is the 1969 production was the first revival of the Lincoln Mystery Plays since the 17th century.
"Lincoln Cathedral commissioned Lincoln Theatre Royal to put the plays on.
"There was a very vibrant cast of young actors and we want to gather them all back together.
"We've been given a wonderful opportunity by the Theatre Royal to have a gala and what we want to do is mark that first performance.
"We want to hear from anyone who may have been involved with that first production or in the audience and tell us about their memories, reminisces or anything they can remember about that performance.
"Then we'll take all of those memories and involve them in the gala somehow, but we haven't quite decided how yet.
"The mystery plays are such a remarkable part of Lincoln's theatre history and we want to keep them alive."
The Lincoln Mystery Plays Trust fundraising gala will take place at the Lincoln Theatre Royal on October 9.
It will include chorale music, extracts from previous plays, and will be hosted by the county's own Hollywood star Colin McFarlane, who played the role of Satan in the 1989 production.
Ian Dickens, artistic director of the Theatre Royal, said: "We're really happy to be working with the Lincoln Mystery Plays Trust.
"The plays are very important to the community and it's essential they raise as much funds as possible so they can keep going.
"We have given the trust the Theatre Royal for that night and anything they manage to raise is theirs to keep."
The next Lincoln mystery play is set to take place next year.
If you have stories from the 1969 production or can help reunite the cast, call the Theatre Royal on 01522 519999.
Alternatively, visit www.lincolnmysteries.co.uk