It takes them way to long to track their boy down, to find him and bring him home. Jack leaves for two weeks while Robby is on sabbatical, and comes back to find Frank has vanished completely. No one knows where he has went, no one has any leads.
Titus is ready to burn the world to the ground, and Jack is just as frantic, but medical school and years of experience have taught him to be way more thorough than his triplet. Jack had returned home to help Titus and Ursula with Grace, Titus' bride, who was heavily pregnant and locked away in the private hospital until she gave birth, had managed to escape, slipping into the night. She's not as careful as Frank, didn't spend years growing up at the side of the Danforth's as the housekeeper's son learning everything she could.
Only Frank was afforded that luxury. She laughs as she's dying, asking for a cigarette, and the baby isn't there where she's lying in the park across the street from the Pitt. Jack doesn't try to save her life and looks the other way as Ursula slits her throat.
It's Jack who finds Frank three months later, working under the name Frank Wheeler. He had hidden himself away, out of their reach just under their noses.
Frank had always been almost too smart for his mates.
Frank, who his the father to a tiny little baby, with familiar defiant blue eyes and a smile that already is all her mothers, and doesn't notice Jack who is rooted on the spot in the middle of an little grocery store in Pittsburgh, rooted on the spot, not daring to breath as Frank smiles down at the baby strapped to his chest.
Everything in him burns in an all-consuming fire, and he has never truly understood his triplets' possessiveness until that moment. It takes another month for them to make their move, to get everything ready, everything perfect for the omega and their pup. Frank doesn't see the needly coming and he sinks into darkness surrounded by three familiar scents that smell like home.
He wakes up in a room he doesn't recognise, with his head on Titus' lap, his fingers running through Frank's hair, and Jack and Ursula talking softly, fussing and cooing over the baby in Ursula's arm.
Titus knows he's awake the moment Frank woke up and leans down, his voice is low and honeyed and makes something in Frank want to trill.
"Welcome home, baby, we missed you."
And Frank hates the small kernel of absolute truth telling him this is where he belongs.