More than 600 members of New Zealand's Defence Force have made a journey across the Tasman for a massive display of military force.
They're among tens of thousands of Allied troops taking part in war games on the Queensland coast.
But it's drawn the attention of a Chinese spy ship.
"We have to learn to communicate, and if necessary, fight as teammates, and the best way to do that is to build relationships during training," US Army Hawaii commander Major General Ron Clark said.
It's called exercise Talisman Sabre - a huge display of military might, held every two years off the coast of Queensland.
It brings together 30,000 allied troops, but an uninvited guest has also turned up - a ship full of Chinese spies.
"They're like electronic vacuum cleaners," Australian Strategic Policy Institute director Michael Shoebridge said. "Anything in the electronic spectrum is what this ship is designed to hoover up."
A state of the art Chinese surveillance ship is making its way down from Papua New Guinea.
"There is one north of Australia at the moment," chief of Joint Operation Lt Gen Greg Bilton said. "We don't know yet what its destination is, but we're assuming that it will come down to the east coast of Queensland."
In international waters, the ship is welcome - and commanders say it poses no threat.
But experts say it's part of a growing pattern.
"We know that the Chinese are increasingly undertaking surveillance of these types of military exercises around the world," Australian National University Professor of international law Donald Rothwell said.
A reminder this alliance of Pacific nations is not the only force to be reckoned with here.