It's finally Saturday. Do you know what that means? That means that the Investigation Squad finally gets to relax and have a day off after a week full of hard work and investigation.

Wait! That's strange. What are those marks on the floor? The Investigation Squad takes a closer look.

"They kind of look like foot prints, but they're way bigger than our feet" Lacey comments.

"I think you're right" says George.

"We must investigate!" exclaims Alex. "There is no way we can relax if we don't know who these foot prints belong to."

So the Investigation Squad, once again, goes off to solve the mystery.

Clues:

-Big footprints

The Investigation Squad writes down what they know.

The Investigation Squad follow the footprints to another room and make another observation.

Look! A pair of boots. But who do they belong to?

The foot prints stopped!

Those boots are heavier than our shoes. They must belong to someone strong!

Clues:

-Big Footprints

-Heavy boots

"I think we should take a closer look at our clues" says Lacey. "Let's observe and record the properties of these boots.

"You're right" Alex agrees. "Let's write down what we see."

Clues:

-Big Foot prints

-Heavy boots:

-bigger than our shoes, heavier than our shoes, shaped like winter boots, color brown, feel rough.

The Investigation Squad found another clue! There's a puddle of water and ice on the counter.

Look! I think someone spilled two things on the counter!

Actually, I think these two are the same thing. They are both water.

You're right! When water freezes, it turns into ice. I think someone spilled ice on the counter and then it melted when it got too close to the fire.

Let's record our observations.

Water has three states: solid, liquid, and gas. When water gets really cold, it becomes ice and turns into a solid. When it is room temperature, water is a liquid. When it gets too hot, it evaporates and becomes a gas.