The only thing I could hope was that the whole time travel thing was too complicated for me to get my head around, and that somehow we had only just missed each other. When we arrived home to Solvit Hall, a tiny bit of me was expecting to see Mum waiting for us with her arms folded across her chest, just like Zoe when she’s cross.

No such luck. I helped Stanley to lug Grandpa’s suitcases upstairs and then headed to my room. It looked just the same as when I’d left it. My bed was still unmade and my Adventure kit was still sitting in the middle of the floor. Right then I made a promise to myself that I’d never leave it behind again, no matter how many suspicious-smelling picnics Grandpa shoved at me.

I opened the bag and pulled out Grandpa’s old leather-bound spy diary. I had found it when I first discovered that I was an Adventurer, and it had been really useful. Now I just wanted something to cheer me up.

I opened it at the beginning, and saw that there was some writing in pencil on the first page. It was kind of faint, which must be why I hadn’t noticed it before. I drew the book under my desk lamp and started to read.

I sat up straight and my fingertips tingled. Grandpa Monty had the right idea! I had to start a diary of my own, and write down every single clue I had collected about my parents. Perhaps there was a pattern I was missing, or a link I couldn’t see.

I raided my schoolbag and found a chemistry exercise book that I had hardly used. I tore the used pages out and put the book on the desk in front of me. It wasn’t as cool-looking as Grandpa’s, but it was mine, and I didn’t care how it looked if it helped me to figure out what had happened to my parents. I took a thick red marker pen and wrote on the front of the book:

I opened the first page and printed CLUES at the top of the page. Then I chose a black pen and started to write down all the clues that I had been given since my parents had gone missing.

1. I will find one parent before I find the other.
2. Neither of them is where I left them.
3. The Partek said that my dad is in a place where. I will never find him, but as they are human-hating cat-shaped aliens, I’m taking it with a pinch of salt.
4. Mum and Dad made a time machine that took them to the Stone Age.
5. Mum left Dad behind in the Stone Age and went off somewhere in the time machine.
6. Dad got into a Partek spaceship.
7. Mum is stuck somewhere between the Stone Age and the present.

On the next page I wrote QUESTIONS. I chewed on the end of the pen for a minute, and then made a list of all the things I didn’t understand.

• Why did Mum leave Dad in the Stone Age?
• Where did she go?
• Why didn’t she come home?
• Why did Dad get into a Partek spaceship when he knows they’re the enemy?
• Where did he go?
• Where is he now?

On the following page I printed SOLUTIONS. Then I stared at the blank page for about ten minutes, trying to think of a plan to bring them home. Finally I took a deep breath and began to write.

SOLUTION 1: Search through time and space until I find them.

PROBLEM: This could take lifetimes.

SOLUTION 2: Find someone to fix Morph so I can control the time machine program, go back to the jungle before I lost them and stop the whole thing from happening.

PROBLEM: The only person I know who’s clever enough to fix Morph is Dad’s rival inventor Dr Demonax, and he’s a demented prisoner with a snot issue and a penguin obsession.

SOLUTION 3:

I couldn’t even think of a Solution 3. I flung down the pen and looked back through my lists, trying to ignore the little doubtful voice in my head that was saying I might never find them. Maybe I just had to wait for the next Adventure. Maybe I would learn more then. The main thing was to keep believing that one day, somehow, I would find my parents and bring them home.

At that moment my SurfM8 50 started to bleep – I had an IM from Zoe.

I glanced at the wall, where my Stone-Age skateboard was leaning. I felt a grin spreading over my face.

Zoe would love the skateboard! I picked it up and then turned to tuck my own board under my other arm. As I lifted it, I saw something thin and white taped underneath it. Another letter!

My heart started thumping – as soon as I figured out the clues, I’d know where my next Adventure was going to be! I pulled my SurfM8 out again and tapped ‘gladiators’ into a search engine. A ton of pages came up, and I could see that loads of them referred to the Colosseum. I’d definitely heard of that – I was pretty sure it was somewhere in Greece or Italy.

I moved on to the next clue and tapped ‘queen egypt carpet’ into the search engine. This time the pages that I scrolled through were all about Caesar, the ruler of ancient Rome.

As soon as I saw the word ‘Rome’, I knew the answer to the third clue. Romans were famous for building straight roads . . . I was going to be visiting ancient Rome! Even better, that was a time in between the Stone Age and the present, so it could be the place where Mum was stuck.

Suddenly all my worries and doubts seemed unimportant. Pretty soon I would be going on another Adventure that involved gladiators, ancient Rome and Caesar, and with a bit of luck I might even find my mum.

Cool or what!