John Hopkins

For now, there is one saving grace.

Fortunately, the whale is swimming close to the surface, allowing Nan to occasionally suck air through her snorkel.

but he could still dive at any moment and take Nan down with him.

And that's not the only horrifying possibility.

Despite the adrenaline, Nan manages to remain relatively composed.

Decades in wildlife conservation have taught her never to lose her cool, even in situations where her life is on the line.

Moreover, the dangerous nature of her work means she's had to accept the high chance of a fatal incident.

But that doesn't stop her pulse from racing.

Right now, as she is helplessly borne along on this underwater giant, gasping for air when she can, a bad outcome seems far likelier than a good one.

If these are to be her final moments, it seems both fitting and ironic that she should spend them like this, at the mercy of the animal she has spent so much of her life protecting.

But just as Nan begins to resign herself to the inevitable, something else kicks in.

It's the afternoon of September the 14th, 2017, in the ocean of the Cook Islands.

Bathed in brilliant sunshine, a documentary crew crowds the side of a boat, fretfully scanning the choppy blue water that surrounds them.

Moments ago, they lost sight of their resident whale expert, Nan Houser, as she was seemingly picked up by a humpback and carried off into the depths.

The anxiety around the boat underscores a grim, unspoken knowledge.

That if Nan has run into an aggressive male, it's highly unlikely she'll come out of this encounter alive.

And meanwhile, a few hundred meters away from the boat, several feet beneath the surface, Nan is still alive, trying desperately to establish some distance between herself and her 45-ton assailant.

Seeing an opportunity, she pushes off from his body, trying not to kick him in the process.

The last thing she wants to do is startle the animal.

Try as she might, Nan can't escape the whale's vast orbit.