This story is a sequel to The Sisters Doo

Twilight Sparkle is a scientific pony. She understands things when they are explained.

Pinkie Pie is... uh... not a scientific pony. And she can't explain anything.

But there are secrets in the Wabe that Twilight needs to know, and only Pinkie has the answers.

A side-story to "The Sisters Doo".

When Twilight receives a letter from one claiming to be a changeling, she is shocked. As she starts reading, however, she soon learns that there is far more to it than she ever suspected.

Reading by Goombasa.

The story had been translated to Russian: Here and Here

Special thanks to PoisonClaw for editing.

For the Weekly Prompt (changelings) of the Hazardous Writing Materials and Challenges

Daring Do seeks a favor from her sister in Ponyville. Due to buried grudges, things quickly get out of hoof. She soon finds herself on her most perilous mission yet... with her biggest fan in the world. In the midst of truth and lies, loyalty and treachery, love and hate, one thing is clear ― some family situations are stranger than fiction.

The story extends in Through the Looking-glass and What Pinkie Found There and The Daughter Doo: Honorary Cutie Mark Crusader.

Many thanks to Honey Mead and statoose for their watchful and helpful pre-reading.

Ckat_Myla and statoose (CatNStat) have started an excellent reading of TSD.