One was going up - using ropes to climb up the mountain to locate alternative cave entrances. The other was going down - deep diving into the cave to help evacuate the trapped boys.
Though there were two Singaporeans involved in the Thai cave rescue efforts last year, both of them have not met each other.
Even when the Thai government arranged an appreciation dinner in Thailand for all volunteers late last year, the two still did not have the chance to say hello to each other.
Veteran diver Douglas Yeo is excited about finally meeting Mr Poh Kok Wee, a rope climbing specialist who runs a company that installs high-rise signs and solar panels in Thailand, at the Istana tomorrow.
"I want to tell him that I am proud of him, knowing that he also volunteered and risked his life in the rescue effort, and we can share some of our experiences and memories with each other," said Mr Yeo.
Mr Yeo and Mr Poh are jointly nominated for The Straits Times Singaporean of the Year award for 2018, and together with 10 other finalists, they will gather tomorrow at the Istana where the winner will be announced at an award ceremony.
The award comes with a $20,000 cash prize and trophy that will be presented by President Halimah Yacob. It honours citizens who have put the country on the world map, persevered through incredible adversity or made the community a better place through selfless acts.
Now in its fourth year, the award is organised by The Straits Times and sponsored by UBS Singapore.
In the running for this year's award are 11 finalists from different walks of life.
They are Thai cave rescuers Douglas Yeo and Poh Kok Wee, teacher Teo Yee Ming, sociologist Teo You Yenn, interfaith champion Siti Noor Mastura, urban farmer Bjorn Low, technopreneur Annabelle Kwok, blood donor Robert Chew, veteran nurse Harbhajan Singh, Mr Nizar Mohamed Shariff and Free Food for All, a charity that provides free cooked meals for the needy, entrepreneur Elizabeth Tan, and couple Kenneth and Adeline Thong who are "parents" to young adults.
They were picked from a total of 74 individuals or groups of individuals who were nominated.
Fourteen judges went through three rounds of selection to decide on 11 finalists. The public also took part in the online readers' choice segment.
The judging panel includes editors from The Straits Times, as well as figures such as social entrepreneur and activist Saleemah Ismail, chef and restaurateur Willin Low and poet and civil servant Aaron Maniam.
While the award recipient takes home the top prize, the other 10 finalists will each receive $5,000, among other prizes.
The prize money is sponsored by UBS. Other sponsors include Singapore Airlines, Millennium Hotels and Resorts, Osim and Tridente Automobili.
Free Food for All founder Mr Nizar said he is already experiencing butterflies in his stomach.
"It will be my first trip to the Istana. I am looking forward to see it and hopefully get a photo with Madam President," said Mr Nizar.
Mr Thong, who is nominated for opening up his house and life to "parent" young adults who do not have a roof over their heads, said he looks forward to seeing the teenagers get to meet the President.
He said: "I also want to talk to Ms Teo about her work on social inequality and hopefully meet others whom we can work together with to restore more caring communities in Singapore."