In a grainy video message from a satellite phone, Joseph says: "Do you see me? I hope so. I need you to help me." He has only 24 hours to find a Red Cross messenger who knows what happened to his mother during a conflict in his African homeland. This might be his only chance to find his missing parent.
So begins Traces of Hope, an online game launched by the British Red Cross last October to show the impact war has on civilians. It's one of a growing number of games being used by charities to communicate their messages.
Dorothea Arndt, new media manager at the British Red Cross, says using a game offered several advantages.
"Games provide a useful story that entices people into finding out more," she says. "We wanted to engage people emotionally in the character's plight. It was also a novel idea; we were one of the first big charities to launch an alternative-reality game."
Alternative-reality games are relatively new and complex. They are designed to get people searching the internet for the fictional and factual information needed to solve a mystery or a puzzle.
In Traces of Hope, for example, players are encouraged to visit various websites to find the information Joseph needs to locate the Red Cross worker. Some of the information is there to direct players to the next goal; some uses real-life material to emphasise the reality of life in a conflict zone.
"It was a lot of work and we were incredibly involved in the development process," says Arndt. "For example, we had to develop partnerships with Reuters and Yahoo! to get the information for the game online.
By digital standards, it was expensive; but it was cheap compared with buying media space."
The complexity of Traces of Hope is unusual - most charities opt for simpler offerings. Leonard Cheshire Disability, for example, created several games for its Creature Discomforts campaign that were based on simple ideas such as catching flies with your character's tongue or rescuing fish caught on fishing lines.
Stephen Elsden, marketing manager at the charity, says simple means accessible. "It was a conscious decision," he says. "We didn't want there to be lots of instructions or keys to press. Simplicity has driven up usage."
It's a claim supported by the figures. More than 150,000 people played a Creature Discomforts game within the first two months of their launch. By contrast, Traces of Hope attracted 7,500 players.
However, 1,868 of them signed up for British Red Cross emails - not bad, given that only 4,000 of the 150,000 Creature Discomforts players did the same.
Arndt says Traces of Hope also generated huge amounts of publicity, thanks to its novel approach, making it a PR victory if nothing else.
The aim of the game
Gobion Rowlands, chair of game developer Red Redemption, which made the Climate Challenge game for the BBC to raise awareness about environmental issues, says both simple and complex approaches have a place.
"The decision should depend on your subject," he says. "If you do a simple puzzle game about climate change, how much information can you get across? But if your aim is simply to raise awareness of your charity, it might be enough."
Rowlands says games have important advantages over other forms of digital communication. "The key advantage is you're talking to people on an equal level; they are no longer passive observers but active participants, so it's easier to build a connection," he says.
"You can also communicate a huge amount of knowledge in a lightweight form and measure what choices people make. One of the big problems with surveys is that people have a strong desire to be helpful when they take part - they give answers just for the sake of it.
A game, by contrast, allows you to find out what people actually do, not just what they say they would do."
Rowlands says the UN World Food Programme's Food Force game is a good example of using games to communicate a message.
"It's made up of five very simple games, such as fixing wheels on a truck or handing out food parcels," he says. "What's clever is that, together, the games create a coherent narrative about world hunger."
But charities have struggled to use games effectively, he says. "Most charity games end up as linear simulations with no choices for the player," says Rowlands. "But games should provide interaction and should not just be TV with buttons you have to press to keep watching.
"A big problem is that these games are rushed and there's little preparation. The design work is often lacking because people think it's expendable, but the design is what makes the difference between a game that succeeds and one that fails."
Drew de Sotto, creative director of Navig8, which made Elizabeth Finn Care's Lionel Blair: Dancing on Thin Ice, agrees. "A game must be playable," he says. "The user must want to play it over and over again."
However, de Sotto thinks Lionel Blair failed on that front. "It began as an e-card, then morphed into a competition entry and a data-collection tool," he says. "We introduced the game element to heighten interest, but it is not a game in the greater sense."
Elizabeth Finn Care regards Lionel Blair as a successful experiment. The charity ended up with 700 new people on its email list and is now planning to create more games.
The use of games to promote ideas about social issues is still in its infancy. According to Rowlands, however, the advantages and widespread appeal of games mean this is just the beginning.
"There are 27.5 million active game players in the UK," he says. "Games are the number one entertainment media for all under-25s and joint number one for under-35s. They are only going to get more popular as those who grew up with them get older."
Creating games is not the only way that charities have spread their messages through play. Commercial online games are also exhibiting some philanthropic tendencies.
Video game firm Sony Online Entertainment, for example, introduced an option in EverQuest, a multiplayer fantasy role-playing game in which players can explore a virtual landscape, fight monsters and interact with other gamers.
The option let players donate money to help the victims of Hurricane Katrina in the US.
In Japan, Save the Children teamed up with an online game firm to sell items to players and thus raise money for victims of the 2006 earthquake in Indonesia.
And after a popular player of the game Star Wars Galaxies died from cancer, fellow gamers held an in-game auction of items that raised more than $13,000 for the US Leukemia & Lymphoma Society.
THE TEENAGERS' VERDICTS
How good are these games? Third Sector boarded HMS Belfast to get the verdicts of four members of the City of London Sea Cadets
Organisation: Leonard Cheshire Disability
Stevie: "These games show what people can do, even with disabilities. The characters made it more fun."
Jason: "The turtle one was the best game because you can always try to beat your own score and work on your technique."
Sophie: "I liked the game best where you catch flies with your tongue."
Cadets' verdict: 4.5 out of 5
DARFUR IS DYING
Organisation: mtvU, Reebok Human Rights Foundation and International Crisis Group
Jason: "It makes you think about what people have to go through just to live."
Stevie: "The bit in the village was difficult to understand."
Joe: "It was a good little game once you got to know it, but I didn't like it enough to play it again."
Cadets' verdict: 3.25 out of 5
LIONEL BLAIR: DANCING ON THIN ICE
Organisation: Elizabeth Finn Care
Joe: "I didn't know what to do. There were no instructions and it was boring."
Sophie: "It might be good for little kids."
Stevie: "I didn't see the point of it. There should have been different dance moves to try."
Cadets' verdict: 1 out of 5.