What can I do at the Travel Agency?

Still not book a ticket out of Yestertide, regrettably.

But the decorations are still interesting, at least.

Tap the toy AIRPLANE to get a message.

Do airplanes have sisters?

Twins maybe?

Look at the Foster Brothers poster.

It looks like some WORDS are removable.

Maybe they're supposed to be repositioned?

Place the words you removed onto the circle around the airplane on the poster. Tap to rearrange them as you like.

There's one more step missing before the poster can help you out.

Have you been to Gio's?

Come back after you've opened the safe at Gio's.

You should now have a translucent disc with – aha! – a colorful propeller design.

Try placing it onto the poster.

Do you have something to attach it with? If not, go to the Post Office for some TAPE.

Now use the disc on the poster again. This time it stays up.

Through the translucent disc you can see some numbers or question marks under each color.

Remove the disc and rearrange the word tiles so the same-colored letters all form real words, then replace the disc to get your hint.

(SOLUTION FOLLOWS)

↓

Rearrange the word tiles so you form the words "theorem," "index," "travel" and "vetted."

Place the disc on the poster to get 3 for blue, 5 for green, and 2 for red.