John Hopkins

Despite Nan's initial certainty that the whale was deliberately protecting her from the shark, good scientific practice demands scrutiny and skepticism.

There have been some studies into altruism in humpback whales, but as far as Nan can tell, nothing as clear-cut as what she experienced.

As more time goes by, she becomes increasingly convinced that what happened to her was not a miracle, but a scientific clue, perhaps indicating something genuinely groundbreaking.

As the weeks turn into months, questions mount.

Did Nan experience a one-off, an arbitrary chance occurrence that has no real bearing on academic research?

Or did she glimpse an aspect of whale behavior that science hasn't yet fully understood?

As it happens, she will soon get a second chance to find out.

It is one year later.

On the south side of the island, Nan is at work conducting field research with a team of marine biologists.

Suddenly her phone rings.

It's a colleague telling her that a humpback whale has been spotted near Rarotonga Harbor.

Nan and her team board the speedboat.

As it putters out towards the reef, she scratches her head.

The details of the tail look familiar, but she has to get closer to be sure.

Humpbacks can navigate with extreme accuracy, and it's not uncommon for whales to return to the same spot twice.

The boat comes to a stop, and Nan gets into her diving gear, her wetsuit, flippers and mask.

Then she peers into the waves.

After a few moments, the dark silhouette of a humpback appears below them, its bulky, elongated body parallel to the boat.

Nan slides off the end of the boat and swims over to the animal.

And the most remarkable of reunions ensues.