In McLaren-Honda's press conference in Bahrain today about Fernando Alonso's upcoming trip to the Indy 500, Zak Brown revealed that the whole thing started as a simple joke.
But when everything was set in motion, the project was turned into reality in a matter of weeks.
"It is one of those where one of your jokes has some truth in it. I said to Fernando pre-Australia: 'Hey one of these days we should do Indy together,” Brown said.
"I threw it out there to see what type of reaction I would get. He joked back and I thought I had thrown the bait in the water and would leave it at that.
"But when Fernando and I were with Eric and Honda in Australia, it came up in a conversation one of the mornings.
"Fernando brought it up and said: 'Honda had an unbelievably great history at the Speedway and I have a dream to win the Triple Crown. I wanted to do Le Mans in the past and would love to do Indy with you.'"
Alonso said that things seriously started to develop a few days after the Australian GP while chatting with Brown through a photoshoot in Los Angeles.
"I received a call from Zak about different things, not this one, and in one moment of the conversation, it came out again the Indy 500 possibility,” Alonso said.
"At that point I was happy that McLaren was considering this Indy 500 entry, as they had won in the past a couple of times.
"I was happy when Zak joined the team last year but I was even happier when Zak was telling me these plans for the future.
"But in a way I was thinking for 2018, as obviously it was only 55 days until Indy 2017."
A meeting last week in China between Alonso, his manager Luis Garcia Abad, Brown and Boullier confirmed that an opportunity existed, and it was the Spanish drivers' choice to take it or leave it.
"I said 'I will sleep tonight' on Friday and on Saturday I would make a decision.
"On Saturday I arrived at the circuit and said, 'Yes this is a good decision for everyone: a win, win for myself, for F1, the fans, everyone'.
"I was not completely sure on Saturday in China if it was still possible to make it so quick, but we had a huge help from Indy, from the Speedway, from the promoter and together with Zak's contacts and Andretti Autosport.
"They helped everything become real in two days."