As Fiona continues to investigate her father's, Declan's, death in Irish Blood season 1 episode 4, with the help of the clues inside his briefcase that he left for her, she stumbles into a series of dangerous conspiracies. So far, Fiona has gotten two people in prison, although she's nowhere near figuring out who really had her father killed.
In episode 4, Fiona's mother arrives in Ireland to convince her to return to the US after getting her life in danger one too many times. But instead of coming back home, both Fiona and Mary fall into a pit of deceit from a man from Mary's past, Father Al, who is also related to Declan.
Father Al is Declan's friend, whom Mary met in Las Vegas years ago. He's a missionary for a charity school in Togo, but as Fiona later finds out at the end of Irish Blood season 1 episode 4, it's all a front, and Father Al is dangerous and deadly. What starts as a happy reunion between Father Al and Mary ends in coercion and murder.
Disclaimer: This article contains major spoilers for Irish Blood season 1 episode 4. Reader's discretion is advised.
Irish Blood season 1 episode 4: Who is Father Al and what does he want?
In Irish Blood season 1 episode 4, Mary meets someone from her past, Father Al. He was a friend of Declan, and they had met many years back in Las Vegas, where Declan first met Mary, who was working as a Blackjack dealer. Father Al also fancied Mary when they were younger, but she chose Declan.

But now that Declan is out of the picture and Mary is on a sort of Irish holiday, their reunion starts getting hot and heavy, and their dinner catch-up ends with a makeout session. This happens in Irish Blood season 1 episode 4, despite Father Al being a priest and running a school for underprivileged children in Togo. But while Mary is having fun with Father Al, Isidora is wary of the priest.
Fiona also starts getting slightly suspicious when Father Al can't answer questions about the charity. She later finds out that there's a good reason for her suspicions because she discovers that the charity/school doesn't exist. Moreover, Father Al has been arrested for money laundering. Even worse, he has kept Mary hostage after a date until Fiona gives him Declan's missing hard drive.
Read more: Does Fiona find the evidence to put Johnny McIntyre in prison?
What is the hard drive in Irish Blood season 1 episode 4 all about?
In Irish Blood season 1 episode 4, Fiona is not the only one looking into Declan's case. The police are also searching for a hard drive after an anonymous person tipped them. Declan's hard drive reportedly contains the access key to a Bitcoin wallet, which is believed to be connected to a money laundering scheme.
The police search Declan's home office for it, and while they retrieve a hard drive, it only contains family pictures. The hard drive the police are looking for is the same hard drive Father Al wants Fiona to give him in exchange for her mother. At the end of Irish Blood season 1 episode 4, Fiona hands a hard drive to Father Al, but it's not the one he wants.
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Who dies in Irish Blood season 1 episode 4? Who killed her?

At the end of Irish Blood season 1 episode 4, during a phone call with Roísín, Fiona learns that Minerva is dead. She was murdered early that morning. The news comes after Father Al sent a video to Fiona, warning her that she/someone is going to pay because of what she has done.
The night before, Fiona hands the hard drive to Father Al in exchange for Mary. But it turns out that it didn't take long for the priest to realize that Fiona had deceived him. She has given him the same hard drive the police found in Declan's office, the one with the family pictures.
As established early in the episode, Declan has given the hard drive to someone for safekeeping, Minerva, his secretary. While Fiona has begged Minerva to hand over Declan's hard drive, the woman refuses because it's the only thing keeping her safe.
In the end, she's wrong because her death marks the tragic end of Irish Blood season 1 episode 4. Coupled with Father Al's threat, he's likely the one who killed or ordered to kill Minerva. Whether he has been able to strong-arm Minerva into giving him the hard drive before killing her is still a mystery.
Read more: Where was Irish Blood season 1 filmed?
What happens during Isidora and Mary's first meeting in Irish Blood season 1 episode 4?

Murders aside, one of the heartfelt and somewhat surprising moments in Irish Blood season 1 episode 4 is Mary and Isidora's meeting. Isidora has been bitter about now knowing that his son has a secret family in the US, hence her dismissive attitude towards Fiona when they first met in the Irish Blood season 1 premiere.
So, when Mary arrives in Ireland and Fiona talks about his father's Irish family, she naturally warns her about Declan's difficult mother. But in a shocking turn of events, an unexpected encounter between Mary and Isidora in Declan's grave ends in a warm embrace.
Isidora warmly accepts Mary in the family, a complete one-eighty from her initial treatment of Fiona. Her initial dismissive attitude wasn't because she didn't like Declan's secret family, but because she didn't like that he kept his family a secret from her. Now that she has acclimated to the fact that Fiona and Mary exist, she has nothing but love for them.
In Irish Blood season 1 episode 4, Isidora also gives Mary an engagement ring from her mother. The ring is intended for Declan's wife, and now that she has met Mary, she thinks the ring has found its rightful owner.
Catch Irish Blood season 1 episode 4 streaming on Acorn TV.