The Island Suspense event in Tears of Themis is something a bit different from the other special events we’ve seen in the game’s five-year history. Following on from the Gladiolus Valley arc, it’s the first ToT event that also forms an important part of the main story and, thus, will be available permanently beyond its initial run, ensuring that new players or those who are behind on the plot don’t miss out.
However, there are still time-limited rewards associated with Island Suspense’s initial duration, alongside several permanent rewards. Many rewards of both types are connected to the encryption codes you can find hidden within the event itself as well as in event trailers and on HoYoverse’s social media. Read on for every encryption cipher in Tears of Themis’ Island Suspense event, where you can find it, and what its decrypted message reads.
There are a total of 90 entries under the Clue Collection > Encryption category in the Island Suspense event terminal, of which 69 (obligatory: nice) can be unlocked by entering a cipher text into the Deciphering menu.
Thus far, 47 of the 69 (again, nice) encryption codes have been uncovered – and, though we list them here, you’ll want to track them down yourself in-game as well if you want to fill out the remaining 21 entries to complete your Encryption codex by the end of the event.
Cracking all (I’m not doing it this time) 69 ciphers satisfies the conditions of “Painstaking Investigator” permanent event task, which also awards you with 10,000 Stellin for your trouble. So for clarity, there’s no time pressure to complete all decryptions by October 17th, 2025 when the limited-time event expires; whenever you’re reading this guide, as long as Tears of Themis servers are still online, you can still plug all of these codes into the in-game Deciphering device and enjoy the rewards.
In order to decipher the encrypted codes, go to the Island Suspense event page in Tears of Themis. This can currently be accessed via the icon on the game’s main screen during the limited-time portion of the event, but will be permanently accessible from the X-Note > Events menu as well.
From the event landing page, select the Terminal icon on the bottom left of the screen.
Choose Deciphering from the options given on this menu, then enter your cipher text into the text box and click Decrypt.
If you’re having difficulty getting a cipher to register, try retyping it into the deciphering box yourself, as I’ve experienced some issues with copy+pasted text not being correctly registered by the game.
(Also be aware that — at least on Android devices like mine — your phone will probably get confused and try to save every cipher as a password; it’s annoying but you can safely just ignore it.)
For a more traditional codes list — including the ones unlocked via some of the ciphers listed above — see our Tears of Themis codes page. If you’re still getting caught up on the main story, you might also like our Tears of Themis Episode 15 walkthrough, which covers the most recent main story chapter that came out in August.