The following article contains an answer for the question: Who gets threatening notes about The Three Springs? , can you please find it? 

Tex Hanlon is in charge of a wildly successful and mysterious advertising campaign for "The Three Springs".  People everywhere are curious what the ads refer to, and even Malcolm Tauber the head of the company Hanlon works for, is in the dark. It's revealed that Tauber's assistant (and Hanlon's girlfriend) Gwen Hughes has created some secret sketches of women's fashion for Tex that will be used in the final Three Springs ad. 
However, other forces are at work. Attracted by the attention given the campaign, Renee Beauchamps asks for a chance to begin work with Hanlon. He agrees, but begins to receive threatening notes related to The Three Springs. A passing motorist, Julian Leighton, picks him up and offers him twenty-thousand dollars to spill the secret. Another wealthy man, Alexander Cardovsky, also asks for information. He's later pressured by two thugs, Mr. Warren and Bert to reveal everything. He buys a toy puppet from a poor woman, Jenny, and finds another note in the toy, asking him to meet her. When he does, he discovers Jenny has been murdered, and he's been set up to take the blame. However, Gwen can vouch for Hanlon's whereabouts at the time of the murder.
The next day Tauber is anxious to run the final Three Springs ad. He's upset when Hanlon balks, but grateful Hanlon kept The Three Springs campaign out of his conversation with the police. Hanlon tells Gwen they need to delay because he needs answers to force the criminals out in the open. Gwen convinces him otherwise and arranges to have the final proofs rushed from the printers that evening. Then Hanlon discovers that Renee has been writing the threatening notes, and she claims she'd hope to frighten him into working with her. Renee says she's being followed and must speak with him later. Gwen sees Renee kiss Hanlon goodbye and is furious.

Tex Hanlon