Dunno. Try Target. If not, get them on a website, like eBay.
there are 4 card packs in the 39 clues series.
you get them in card packs
You have to play all the missions and get all the books and the card packs
you git them in the books and the card packs
you can get card packs and register them online to win prizes
You can purchase card packs with codes for The 39 Clues. Examples of codes are: G69CTWHC9T, G69CKR3K9T, 223M6DTNX2.
you git them in the books and the card packs
well heres one code P3KPMWPGXP
You need to play the missions, buy the books, and buy the card packs. Enter the card codes. Then you can gather clues.
16 Randomly inserted cards! No two card packs are alike!
You have to buy packs of The 39 Clues cards to get the card codes. Card codes can only be entered into one person's card gallery, so you can not use a card code that someone else has already used.
you must have all 39 Clues, which you can get by: play missions from the 39 clues website, reading and registering the books online, and entering cards that you can get from the books or card packs. sorry, but i haven't even done it.