The 39 Clues Wiki
The 39 Clues Wiki

The Enemy Within is the second Doublecross Mission. The mission is unlocked by adding Mission Hindenburg cards to your account. Once you're done, open up Casebook Two and test what you've learned here!

Message from Cahill Command[]

Hi there, Agent

Thanks for dropping by. I know you've been quite busy lately.

Sorry, what's that you say? You don't know what I'm talking about? Well, let's get you up to speed shall we?

As you may have noticed, the Cahill Web has been compromised. SOMEONE has hacked in and hidden some rather unflattering messages in various entries. Actually, perhaps "unflattering" isn't the right word. "Treacherous" would be better. Someone is clearly trying to turn the Cahills against each other, which is the LAST thing we can afford while trying to stop the Outcast.

That's why I asked you here today. We found the IP address of the hacker, and are pretty sure we've located the traitor... YOU.

That's right. All the evidence suggests that YOU vandalized the Cahill Web in order to create a diversion.

What? You DENY it?! Ha! All right then, fine. I'll give you once chance to clear your name. Go through the Cahill Web, find the vandalized pages, and discover the real culprit.

Good luck. You're going to need it.



Your Mission[]

You are framed for something you didn't do. You are given a chance to clear your name by finding who is the real culprit. Navigate yourself through the Cahill Web and find the vandalized pages, track the IP address of the hacker.

Use the cards as a guide to help you track the hacker

Track the Hacker[]

I Like Useless Facts - Grace Cahill[]

You will start from here. When you hover the mouse on Grace Cahill picture, you'll see a big red cross with a word 'TRAITOR'. Click on that and it leads you to the next page.

I Like Useless Facts - Marie Curie[]

This is the next page after you clicked on the picture. Search for 'Blatant Lies', and click on it. It will lead you to the next page.

The Boston Beacon - Mysterious Fire Kills Married Couple[]

This is the article talking about the fire that kill Amy and Dan's parents, Arthur Trent and Hope Cahill. The image is clickable. Listen to the recording of a neighbour calling 911 about the fire. The recording reveals the order of the windows you need to click. 1st row left window - 3rd row right window - 4th row left window. After you clocked the three windows in order, it reveals the picture of after the fire. Click on it to get to the next page.

MIT Compass - Beloved Professor Dies in Fire[]

This is a blog written by one of Arthur's student. The message 'He Had It Coming' is clearly something new. Go on and erase the message on the right, and it lefts you with several letters. It said 'Research trips'. Search for it on the passage and click it to get to the next page.

The Truth is Out There - Area 51[]

Hover your mouse on the UFO, and it reveals a red message below left by the Outcast. There's a morse code message. Decode it and you get 'CERN'. Type the word on the search bar, and click on GO button. It leads you to the next site.

International Physics - Large Hadron Collider May Destroy Earth[]

This page talks about some rumors that CERN may cause a catastrophic blackhole that can destroy the Earth. Look at the list of website references. One site looked strange. Click on this site -

IP Tracker[]

When you clicked on that site, you got an 'Error 404' page, saying the page is not found - page is blocked because of a suspicious IP address. Copy that IP address and input it on the IP tracker. You see the tracker do its work. But, as soon it is almost finished, the trace is terminated. The Outcast had found out about you, telling you to leave everything and don't mind his business, or else he will harm us.

Ian apologizes for the blame he puts on us, now that he knows it was the Outcast who hacked the Cahill Web.

Casebook Two[]

Answer the questions correctly. You will find the answers while you are navigating yourselves in the Cahill Web.