Nathan, Caroline and Jack were explorers in the dessert. They came prepared though, bringing lots of water and other supplies so that they wouldn't risk their lives. The three were looking for something they had left behind on their first trip to the dessert. That time though, they almost ran out of supplies and Jack collapsed of dehydration. Anyway, having returned to the airport, Nathan realized that they had left the gem that went to find in the dessert in the first place. Caroline, who is usually referred to as the 'prepared one' and the 'the fusspot (which was trues), predicted this, so she put a tracking device on the gem; something, which initially, Jack and Nathan didn't approve of. So here they were, walking back to the cave wear they found the gem in the first place. The gem was purple, like all gems found in the dessert caves, and sparkled in the sun. The strange thing was that Nathan was carrying the gem, that wasn't the strange bit though. The strange bit was that Nathan felt like he could pinpoint when he lost the gem. He said that it felt like that when he lost it, the sun started screaming. Caroline thought that it was impossible and Jack agreed with her. So off they went, back down the trail they went to get this gem in the first place, making sure to restock for they went to go and find the gem that they had lost.
The Doctor was in his lab in U.N.I.T HQ working on one of his latest experiments. Joe was already in the room, sitting on a brown seat with beige and red leaf patterned cushion which was positioned only a few meters away from the Tardis door. She was reading a relatively thick book with a brown cover. It was sunny outside, around mid-twenties to very early thirties on degrees Celsius temperature. The Doctor's experiment was a contraption that was quite hard to explain. The only thing that could be made out of it was that it had straps, almost like strap on a bike helmet, which went around the bottom of your face. "It's a nice day outside. Isn't it?" Joe commented, not looking up from her book.
"Really?" the Doctor replied, "I haven't exactly had a chance to look," he added.
The Brigadier entered the room with Sergeant Benton walking beside him on his right side. They were both in U.N.I.T uniform. The Doctor sensed the Brigadier had walked in on account of the sound that his saluted as well. After all, whilst she had grown into the role of the Doctor's companion, the Brigadier was still her boss if you like.
"At ease Miss Grant," the Brigadier said as Joe sat again. "Doctor?" he questioned.
"Oh. I'm sorry," the Doctor announced sarcastically pretending to not have noticed the Brigadier and the Sergeant. "Were you talking to me? Morning Benton."
"Morning Doctor," Benton replied, smiling.
The Brigadier looked like he was getting slightly impatient by needless, time wasting talk. "Yes. Now can we please get on with what I came here to talk about?" Everyone started listening more closely, realizing the Brigadier was getting impatient. "A party, of three people, was on an expedition through the dessert looking for a purple gem known as the Tirimatta or just the Tiri for short. Once recovering the gem, they made their way back. The thing was they lost it. So they went back for it…"
"Where is this going Brigadier?" the Doctor interrupted impatiently.
"The point is they went back to find the gem and they never returned," the Brigadier said, raising his voice and speaking louder.
"So? What's it to me? I'm sorry Brigadier," the Doctor got up from his seat and started walking around, "But I don't think that people aimlessly wandering into the dessert, to look for emeralds and gems that they shouldn't be tampering with, is anything to do with U.N.I.T ," he replied. He went to the window of his laboratory room.
"Oh but it is Doctor," Benton announced, using the calming voice that he always used, "You see, rightfully, they insisted on using a GPS tracking which was tracked them on one of their computers ."
The Brigadier continued explaining, "Once the neighbors and mailmen saw that the post was building up to one of the flats of the explorers, they knew something was up. They called the police and one thing led to another. Eventually, we got involved since they were looking for an extraordinary gem they said."
"So what are saying we should do about it?" Jo asked.
"We want you to do what you always do of course... Help! Research and find out as much as you can."
"Well I suppose that if you want us to… Help, then I think that we best get on a flight, or transport, to wherever this is," the Doctor said. He walked towards the Tardis then went inside. He closed the door behind him as Jo, the Brigadier and Sergeant Benton listened to what was going on inside. A couple of explosions gave off inside as Jo jumped to hear the sound. A fainter version of the classic Tardis whir started to kick into motion. But something then sounded wrong. The Tardis sounded almost as if it was starting to groan. The whir, as faint as it was before, soon died out into a silence. Everyone listened.
"Uh… Doctor? Doctor what was that? Are you alright in there?" the Brigadier questioned.
The Doctor then staggered out of the Tardis with smoke steaming out of it behind him. "I think we… I think we should use-use a different method of transport," the Doctor said, once recovering. "But, on a more serious note I think that this could be more dangerous than we thought."