"I haven't done this before," I say. "It's not easy."
"Do exactly what I say and you'll be fine," she says. "Curl your fingers around and hold it at an angle to the vertical. That's it. Now throw."
The two of us watch the little boomerang soar over the grass then plummet into a cowpat. "This isn't easy," I say, as we set off to retrieve it. "Are you sure they ever come back? Maybe it's one of those urban myths for wee boys."
"The big boys on Bondi Beach had no trouble with their boomerangs," she says.
"That's just tacky," I tell her. "And tactless. Just because I have skinny legs and don't know how to hold a boomerang. It's not a survival skill in the West of Scotland. I can dance, dribble a ball and solve differential equations. What more do you want?"
She raises her eyebrows in a manner that says way more than words. "It is a beautiful object," I say, studying the images of Australian animals, painted on the polished wood. "But it's very annoying. My hunter's instincts, honed by millennia of male evolution, should make this easy for me."
"Your hunter's instincts?" she says.
"The ones that make me good at throwing a javelin and parking a car," I tell her. "While you can cook, sew and find things in cupboards. That's your gatherer's instincts."
"Shut up and throw the boomerang," she says.
"I'll try one more time," I say. "Then I'm going to the pub. Why couldn't you get me a present from Australia that wouldn't make me look an idiot?"
"I was only there three weeks," she says.
"Very good," I say, grabbing the shit-covered shaft. "Read the instructions again, will you please?"
"Stand at an angle to the wind," she says. "Hold the boomerang with one of its aerodynamic arms pointing away from you. Throw overhand and snap your wrist to make it spin. Once it's in flight do not look away. If you lose sight of it, adopt the 'mystery boomerang position'."
"I love that bit," I tell her.
"Turn your back, cover your head with your arms and crouch down," she reads. "If the boomerang hits you in the back it was a good throw."
"Last chance for one of those," I say, throwing hard, snapping my wrist and watching with pleasure as the little flying-machine soars through the air and starts banking left. The ground comes up and smacks it some distance away from us, but it's the first sign that I'm getting the hang of this.
"Always stop on a high when learning a new skill," I tell Susan in the pub later. "Makes you keen to try again. What was the best part of your holiday in Australia then?"
"My boy took me out for dinner on the last night, to the Melbourne restaurant where he's chef. I got him all to myself for the first time in years and we chatted for hours. It was a lovely evening."
She studies the bubbles in her beer. "He will come home," I tell her. "In a year or two."
"I'm not so sure," she says. "They've a great life out there. I think it'll be a long time before I see him again."
"Family's too important to him," I say. "He'll return, same as you. You went all the way there and flew home again. You're a bit of a boomerang, yourself."
"Elegantly curved and aesthetically pleasing?" she says.
"Comes back covered in sh...," I start to say, when my hunter's instincts sense her intention, I swiftly adopt the mystery boomerang position, and her raised hand passes harmlessly over my head.