Mako was his own secret-keeper.
He did not like the pity or the pain when he revealed the stories of his past, and he did not like the questions that arose from them. So after awhile, all those stories became secrets, and they were special because they hurt. The details were hidden from the world. They hurt deeply and would not heal, scarring his insides with the memories of cold and lonely nights, of fire bursting from his hands, of the tears stinging his eyes with the realization that they were gone, gone, dead.
His heart was as scarred as his skin.
He missed his father very much.
He had run from the crime scene, ran from his parents' bodies that had crumpled in the alleyway. His grip on Bolin's wrist was tight and unforgiving. The first cut had been made, and the blood spilled deep inside. He could never forget the sickeningly hollow sound of his father's body falling to the pavement, of his mother's crashing against metal trash bins. He ran away, far away. They were empty now and there was nothing to go back to; he had to remind himself of that.
They had lost their souls.
After they had hid, blocks away from it all, panting and crying, his despair manifested quickly. The firebending that he had always been able to control burst forth from his palms; Bolin shrieked with fear and awe, and Mako clasped his hands together to stop it.
The burning hurt and made him scream and writhe on the ground, but it dulled the real wound.
So when Korra found those scars beneath his gloves, stretched and pink, she laid her fingers over them, feeling the texture, feeling the secret. It made him nervous, just the tiniest bit nervous, but she placed her hands over his with calm certainty.
She had hands that healed.
So when he opened his secret box, everything came spilling out at once. She listened quietly, holding his scarred palms in her hands, and he told her where, how, when, why.
He told her how the man's eyes were livid.
He told her how his mother screamed.
He told her how his father fell.
He told her how they ran.
He told her of the burning.
He told her.
Mako was somewhat surprised when her hands drifted up to his cheeks that his scars had not faded any, but he knew not all scars were visible. Korra held his face in her hands, in her healer's hands, and she kissed his tears dry.
His hand drifted up over hers, holding her to him, warm and loving, and he knew, he knew.
She was his healer.
She was his secret-keeper.