Patrick Skinner, 3, and 14-month-old Ellen Walsh lived most of their lives less than a block apart, but it was a pure twist of fate that brought them together -- the two met only after being placed on Britain's heart-transplant list.

Devon and Kevin Skinner watched their son suffer from leukemia and chemotherapy that weakened his heart to the point where he collapsed in his mother's arms after heart failure. Stefanie and Ian Walsh knew that their daughter would face significant health challenges after pre-natal scans revealed that her arteries were arranged in the wrong position.

Despite the fact that they were nearly neighbors, it was the months of waiting for a heart transplant that brought the children -- and their parents -- together. "It was a terrible time but was made a little bit easier by having Stef and Ian there," says Patrick's mom, Devon Skinner.

Then, after sharing the agony of the unknown, the Skinner and Walsh families held each other's hands in the waiting room as their children received tandem heart transplants. Patrick and Ellen each received a new heart on the same day, in the same hospital -- a medical first in Britain.

Stefanie Walsh, 30, calls the timing nothing short of "remarkable:" "It was enough of a coincidence that we lived so near and our children both needed heart transplants. But then to receive them on the same day is unbelievable." Patrick's mother Devon is equally gobsmacked. "I feel very, very proud that my son has made medical history," says the 25-year-old.

As for Patrick and Ellen, the two are still best buddies, now with hearts on the mend. Their mothers foresee a long and happy future for the two -- and maybe even a lifelong romance. "Me and Stef already have the wedding day all planned out," says Devon Skinner.

Now that's what I call a happy ending.