"Yes. Quite convenient, that." 

Hmm, they had a goal here...he pulls his scattered thoughts together and remembers. "Would you still like to enlist the help of a local mage to protect the dreamshard? I can investigate a few of Father's contacts." 

Nod nod. "You would know better than I, but do you think they need to see the dreamshard? Maybe we can just commission a magical safe..."

"With the most secure forms of magical safe, it's impossible to take anything out or put anything inside without the mage's cooperation," Raven contributes. "Ice magic can freeze an area in time so that nothing inside it can change or move, which means nothing can go in or out."

Cat nods. He's broken into more than one of those in the past, and it wasn't easy. "That shouldn't present too much of a problem unless you're likely to need access to it in a hurry. We can find a box or something to put the dreamshard inside, so they can't see it directly, and then the box will go in the safe."

"Impressive." Time magic is one of his few weakness. "And it should work. Thank you."

"You're welcome." 

Cat writes to one of the names in their father's address book, an Ice mage who Father hired last time he needed something put in a safe. He gives the letter to a runner and tells the boy he'll tip extra if he waits for a reply.

While they wait, perhaps Felix could teach them some more about dreamshaping? 

Raven gets out paper and pen so she can take notes, already noting down from memory what Felix has told them so far. 

Right. Back from the top. They are dreamshapers now, this means that every time they fall asleep they will get access to their dreamshaping. Which can be used to expand their pocket dimensions and create portals. It's possible to watch passively as your pocket dimension expands without your input, or take direct control over it. Pocket dimensions exist overlapping or "adjacent" to regular space. When someone places a portal, the portal will connect the two bits of corresponding space in both worlds.

Details vary per dimension, but typically one can't change portions of pocket dimension that already exists. What can be created varies, but one will usually be able to recreate things and patterns they've done in the past.

Raven, of course, takes notes on everything.

"Did your pocket dimension travel with you when you arrived here," she wonders, "or is there still a part of it in your world?" 

"It stayed back in my universe... I couldn't expand it from here. The bits of dimension I've created here are entirely new."

"It's a pity they aren't connected, or you could use that to go home." She writes this down, too.

"Can you tell what's happening in the old part of your dimension?"

He deflates minutely before steeling himself.

"It felt like someone's else dimension."

"Can we detect dimensions belonging to others, then?"

Nod. "You feel where they overlap relative to yours. And you can create portals between yours and them."

"Can you teach us how to do that now, or do we have to wait until we fall asleep?" 

"It's not very complicated, but actually learning does require you to sleep. The best help I can give you is that it feels like digging a tunnel... Except it's in four dimensions and you can pick the conditions in which it will open or close."

"What kind of conditions?" 

"Varies. A lot. Each dreamshaper has a theme. Mine is fire or warmth. I can make Keys be things like 'move a flame in a circle' or 'rub your hands until they warm up' or 'skymage writes with fire'. Other themes include various weather conditions, things done to shadows, emotions, family relations, doing math problems, and so on. It makes it hard to guess."

"Must the key be related to the dreamshaper's theme?" Raven asks. "Or could you have a key that was completely unrelated to fire?" 

"It must," he confirms. "Flexibility varies per dreamshaper. I can't make a key unrelated to fire, even it's something like making fire go out."