Arthur and Lucy Casarez contracted with Blas Garcia, who purported to be a representative of the Albuquerque Fence Company, for the construction of a new home. Blas introduced the Casarezes to Cecil Garcia, who agreed to make a loan to them to be used as a down payment on the project. Cecil then obtained a loan from Rio Grande Valley Bank in the form of a $25,000 cashier's check payable to himself, which he indorsed over to Lucy Casarez. Lucy indorsed the check with the words ‘‘Pay to the order of Albuquerque Fence Company, Lucy N. Casarez'' and delivered it to Blas Garcia.

Claiming he was following Cecil's instructions, Blas indorsed the check with the words ‘‘Alb. Fence Co.'' and gave the check to Cecil. Cecil signed his own name under ‘‘Alb. Fence Co.'' and presented the check to the bank in exchange for $25,000. The Casarezes soon learned that Blas and Cecil Garcia had never been in any way affiliated with or employed by the Albuquerque Fence Company.

Explain whether the unauthorized signatures of Blas and Cecil Garcia invalidate the special indorsement to Albuquerque Fence Company.