'Arrow's Paul Blackthorne on Lance Losing 月桂树 and His Relationship with Mama Smoak 

Playing EXCLUSIVE: 'Arrow's Paul Blackthorne on Lance Losing Laurel and His Relationship with Mama Smoak: 'Maybe She's His New Cornerstone'

, Paul Blackthorne has now faced the on-screen heartbreak of losing one of his daughters three times over, a statistic that might qualify him as the unluckiest character on the CW show if it weren’t for the blood-soaked family tree of titular hero Oliver Queen (Stephen Amell).

But Blackthorne says that preparing for the death of Laurel (Katie Cassidy), who was killed in a recent episode while fighting as the Black Canary against

season four baddie Damien Darhk (Neal McDonough), was unlike facing any of his character’s other tragedies because for those, the unstable police captain always had his eldest daughter by his side.

“I’ve spent a lot of time with Lance now, and Lance has spent a lot of time with Laurel. To find the emotional depth of that wasn’t difficult, because we’ve had so much emotional stuff together,” Blackthorne explained to ET of filming his final scenes with Cassidy. “We’ve played this really close father-daughter relationship for a long time.”

“And then, of course, the other side of that is that, as an actor, you’re losing someone like Katie Cassidy, who’s just been so amazing to work with these last four years,” he added. “I’m really, really sad to see her go.”

#Arrow tonight 8pm @thecw @cw_arrow Big night. #LaurelLance #BlackCanary @katiecassidy

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After Laurel’s death, the actor played his character as a man in denial, understandable given that younger daughter Sara (Caity Lotz) returned from the dead twice before crossing over to become

White Canary. But once Lance began to accept that his eldest daughter was gone for good, the reality sank in.

“Lance was terrified of not just his daughter dying, but dealing with that grief without someone like her around to get him through that,” Blackthorne said. “Obviously, it’s not going to go away overnight. Something like that stays with somebody forevermore. It’s a huge loss that’s going to scar him forever.”

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Star City’s traumatized police captain does have one new bright spot in his life, in the form of a budding relationship with Felicity’s (Emily Bett Rickards) mother, Donna Smoak (Charlotte Ross), with whom Blackthorne says his character is “basically in love.”

“Laurel was always the cornerstone of Lance’s life, his moral compass,” he explained. “What is interesting is exploring that relationship now between Donna and Lance, in terms of how that develops. Maybe she’s his new cornerstone or moral compass.”

“She’s such a contrast to [Lance’s ex-wife] Dinah (Alex Kingston),” he added. “He probably shakes his head a lot as to how this has happened. But she has such a good heart, she’s got such a good soul. Truth and love goes a long way. She represents that.”

WATCH: \'Arrow\' Boss Reveals 4 Reasons Why Laurel Was Killed

That Donna harnesses the light for one of Star City’s embattled heroes proves that the apple doesn’t fall far from the tree. Felicity provided the same kind of support for Oliver as the embattled hero’s teammate-turned-love interest before the pair recently broke off their engagement. And while Oliver is no longer romantically involved with either of Lance’s daughters, the fact that the police captain could still potentially end up as the Green Arrow’s father-in-law is a prospect Blackthorne finds “hilarious.”

“That would be an interesting scenario, wouldn’t it?” he observed with a laugh. “There are times when we’ve had that sort of fatherly moment. It’s nice exploring that, especially with Stephen. He’s great to work with.”

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recently wrapped filming on its fourth season, but Blackthorne is wasting little time on R&R. Instead, the actor is readying for a trip to Vietnam with Save the Rhino International, a cause close to the animal lover’s heart. He’s created several T-shirt campaigns with organizations like Air Shepherd, who work to stop ivory poaching on the ground in Africa, and his latest -- launched with one of Blackthorne’s own heroes, Arsenal soccer star Aaron Ramsey -- aims to raise awareness that 90 percent of ivory poached in Africa ends up in Vietnam.

Greetings one & all. Anyone buying a 'Save the Rhino' T-shirt on the link in my bio has their name thrown in the hat to win this one signed by the Arrow cast... In case you're wondering what this whole Rhino thing is about, and why @aaronramsey and I have launched this 'Save the Rhino Vietnam' T-shirt campaign, here's why: 95% of the world's Rhino species have been wiped out. Of what's left, 90% of the Rhino horn that's poached in Africa today ends up in Vietnam... At the current rate of killing, a creature that has been around for 50 million years, will be extinct in TEN years. We can't let that happen. That's why I'm asking you to support this campaign and buy a T-shirt on the LINK IN MY BIO and that's why I'm heading to Vietnam on May 19th to ask the people of Vietnam to help save the rhino.... Rhino horn cures NOTHING - It's the same thing as your fingernails! All proceeds to @savetherhinointernational Thank you one & all. Myself, Aaron and Rhinos everywhere appreciate your support very much...

“I’ve always been a nature and wildlife lover, I’m just one of those people,” Blackthorne said. “When it became apparent to me in recent years that these species of elephants and rhinos were being poached -- toward extinction, at the current rate of killing -- it disturbed me an awful lot.”

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