Vintage Lot of 4 Alfred Hitchcock & the Three Investigators Mystery Series #1-4, 1964-1971.   3 hardcover and 1 paperback.  Hardcovers are Random House, paperback is Scholastic.

#1 The Secret of Terror Castle - hardcover 1964.  Slight wear to cover; otherwise excellent
#2 The Mystery of the Stuttering Parrot - hardcover 1964.  Pages are detached at spine; otherwise excellent

#3 The Mystery of the Whispering Mummy - hardcover 1965.  Ex-library book, some wear, clear tape on spine cover, pages have been reglued to spine.

#4 The Mystery of the Green Ghost - paperback 1971.  Creases & light wear to cover; otherwise very good.

From a smoke free, pet free home.