In late April 1832, a ship carrying laborer John Ruddy rounded the Irish headlands and plowed west across the Atlantic.
Ruddy, 18 and poor, was sailing for Philadelphia with dreams of a better life.
By August, his body lay buried near the new railroad he'd been building in Chester County.
His skull, unearthed last year, had been crushed, as if someone had smashed it with a blunt instrument or projectile.
That's the way Dr. Matthew Patterson sees it.
Patterson is a Lancaster dentist with forensic expertise. He's part of a volunteer team trying to unlock the secrets of Duffy's Cut, the site of a 19th-century mass grave and present-day archaeological dig near Malvern.
Ruddy was one of 57 young Irish immigrants buried in the narrow valley 177 summers ago, ostensibly after dying of cholera.
What's strange about the case, Duffy's Cut diggers say, is that none of the Philadelphia and Columbia Railroad workers made it out of the valley alive. The survival rate for untreated cholera victims is typically 40 to 50 percent.
Tantalizingly unproven is whether some of the workers were murdered by anti-Irish vigilantes, as Patterson and his friends suspect.
Meanwhile, the lost crew has not gone unsung.
A "Duffy's Cut" song has been written by Irish musician Wally Page.
Tile Films, a Dublin production company, created a 2006 documentary called "The Ghosts of Duffy's Cut." The title refers to the fiery blue-green apparitions said to dance over the graves by night.
News of the project also has circulated widely on this side of the ocean.
When last chronicled in these pages, 13 months ago, the team members were on the brink of excavating the main burial site.
They've made progress since, recovering the remains of four skeletons - including two skulls with signs of trauma. And they've tentatively tied the "John Ruddy" of the sailing ship manifest to the first set of bones uncovered.
However, Patterson says more money is needed to continue sifting through the tree-studded hillside and positively identify the remains through DNA testing.
"Right now we're stalled," said Patterson, a Celtic heritage buff who helped organize the two-year-old Lancaster County Irish-American Cultural Society.
On top of it all, he added, property owners in the adjoining subdivision are pressing the team to finish their privately funded volunteer project by the end of the year.
That will be difficult, said William Watson, the Immaculata University history professor who originally stumbled across the mystery with his twin brother, Frank.
"It's going to be a frenzied summer."
It's already been an interesting 10 years.
The Watsons learned of Duffy's Cut after poring over records saved by their grandfather, a former Pennsylvania Railroad employee.
Something about the documents was fishy, Bill Watson said. "In this case [the supposed cholera victims] all died and that set off a kind of alarm for us."
For another thing, Watson said, hinting at a coverup, the railroad had apparently suppressed information about the deaths.
Descended from Irish and Scottish forebears, Watson said, he feels kinship to the dead workers and an obligation to expose a shameful historical chapter "that has fairly consistently been ignored."
Mass immigrant burial sites are known to exist in other railroad corridors.
"There's a saying that under every mile of track there's an Irishman," Watson added. But Duffy's Cut was almost in his backyard.
The brothers first sank spades there in 2004, the same year the state erected a historical marker. They turned up nothing.
In 2007, they brought in ground-penetrating radar. Lancaster-based Enviroscan Inc. helped them pinpoint an underground anomaly that indicated a mass grave.
On a chilly March day a few days after St. Patrick's Day 2009, then-Immaculata student Robert Frank was doing a pick-and-shovel test dig when he and a classmate spied a weird-looking tree branch.
"It ended up being a tibia," Frank said.
They also recovered a piece of human jaw bone and showed it to Patterson, a Patterson/Votilla Dentistry partner trained in forensics at the Armed Forces Institute of Pathology.
The first thing Patterson noticed was that the upper right front molar had never grown in.
That particular genetic defect is almost unheard of, said Patterson, who began volunteering for the project last year.
During a May trip to Ireland, he studied the prevalence of the hereditary defect, gave Duffy's Cut presentations at dental schools in Cork and Dublin and dined with "The Ghosts of Duffy's Cut" producer Dave Farrell, who is planning another film about the saga.
The story is "huge over on the other side of the pond," Patterson said.
It's already known that the present-day Ruddy family of County Donegal, Ireland, where John Ruddy grew up, has the missing molar trait.
And the skull the researchers believe is Ruddy's has revealed much.
Marks on the teeth and traces of muscle attachments to the bone told Patterson that Ruddy had a powerful build and evidently clenched his teeth when he did heavy lifting.
He apparently didn't brush daily because he already had gum disease at 18. But there was no sign of tooth decay from his spuds-and-buttermilk diet.
Ruddy had no cavities because he couldn't afford sugar.
The "potato people" of Ruddy's social class starved between crops and were among the poorest Europeans, according to John Ahtes, an Immaculata College history professor who said he's become "addicted" to the Duffy's Cut investigation.
Ruddy boarded the barque John Stamp with little more than the clothes on his back. He quit the rough pastures and bogs of his homeland with perhaps more than a little sadness, Ahtes conjectures.
"Coming to America was a trauma and something done out of necessity."
Philip Duffy, an Irishman who'd established himself in the United States a generation earlier, met Ruddy and other men on the Philadelphia docks.
Duffy was recruiting laborers to push the railroad across the roughest, costliest stretch of its 82-mile route.
The men, who hailed from the Irish counties of Donegal, Tyrone and Derry, lived in a shanty. They left behind clay pipes and shoe buckles later spotted by the archaeologists. They worked long, hot days constructing a causeway to carry the tracks through the ravine.
But the 1830s cholera pandemic soon found its way into the valley. Some men tried to leave and were turned back, Patterson and his friends theorize; a local militia-like force called the East Whiteland Horse Company might have done the turning back.
Forensic evidence suggests that some of the men were executed.
Anti-Irish and anti-Catholic sentiment was rampant in the country at that time. And the newcomers were easy to single out, Patterson said.
"They dressed differently. Here's these guys who looked, not like cavemen, but pretty primitive. So many were considered disposable. ... It's the dirty underbelly" of the American Industrial Revolution.
The first few victims were buried in coffins. The rest were tossed together in a jumble "and dirt was thrown on them," Patterson said.
Work on the cut resumed in the fall and steam trains soon pounded over the graves.
The railroad was later straightened. Modern Amtrak trains bypass the cut, which has long since grown up in brush and ghost stories.
An 80-foot tulip poplar soaring above the exposed bank will have to be removed to complete the dig, Patterson said.
Testing DNA from dental pulp inside a victim's teeth would reveal genetic ties to both the person's parents, he added. If no pulp survives, DNA from the harder dentin layers could help researchers trace maternal genealogy.
The long-range plan is to rebury the immigrants in Ireland, or in a Bala Cynwyd cemetery.
Meanwhile, Patterson said, "the bodies are in danger" because tree roots have snaked through the bones, and opened channels for rainwater.
The rest of the tale is bursting to come out, Patterson added.
"It's really wild. It's a detective story. These guys want their story told."
Jon Rutter is a staff writer for the Sunday News. His e-mail address is firstname.lastname@example.org.