---
1. Talk to Squidward; get Squidward's hat.
2. Go to Sandy's treedome; get Sandy's toolbox.
3. Go to Mr. Krab's; get the key.
4. Go to the Chum Bucket; unlock Plankton's door; put on the hat; retrieve the sponge.
```javascript
// get the hat
const squidward = document.getElementById('squidward');
const squdwardHat = document.getElementById('hat');
squidward.addEventListener('click', function () {
player.inventory.push(squidwardHat);
squidwardHat.classList.add('hidden');
});
// get the toolbox
const sandy = document.getElementById('sandy');
const sandysToolbox = document.getElementById('toolbox');
sandy.addEventListener('click', function () {
if (player.inventory.includes(squidwardHat)) {
player.inventory.push(sandysToolbox);
sandysToolbox.classList.add('hidden');
} else {
// show a message to the player that they need to get the hat first
}
});
// get the key
const mrKrabs = document.getElementById('mr-krabs');
const mrKrabsKey = document.getElementById('key');
mrKrabs.addEventListener('click', function () {
if (player.inventory.includes(sandysToolbox)) {
player.inventory.push(mrKrabsKey);
mrKrabsKey.classList.add('hidden');
} else {
// show a message to the player that they need to get the toolbox first
}
});
// use the key to unlock the door
const chumBucket = document.getElementById('chum-bucket');
const planktonDoor = document.getElementById('plankton-door');
chumBucket.addEventListener('click', function () {
if (player.inventory.includes(mrKrabsKey)) {
planktonDoor.classList.remove('locked');
} else {
// show a message to the player that they need to get the key first
}
});
// put on the hat and retrieve the sponge
const plankton = document.getElementById('plankton');
const sponge = document.getElementById('sponge');
plankton.addEventListener('click', function () {
if (player.inventory.includes(squidwardHat)) {
sponge.classList.remove('hidden');
} else {
// show a message to the player that they need to get the hat first
}
});
```