Under the Microscope (Infections, Cave)
(Published on 1. November 2025, 16:05 by gdc)
Episode 2 of the Dr. Norma L. Dokes Saga. I decided to go with cave rules instead of a path this time. According to testers (thanks everyone), it should be around 4 stars. See below for an example puzzle. Hope you enjoy!
Infection Sites: Each digit matching its box number is an "infection site". Each row and column contains an infection site. They are infected.
Infections: Infected cells infect every orthogonally adjacent cell with a smaller digit. Infections keep spreading until no infected cell has a smaller uninfected orthogonal neighbor. (Every infected cell can be traced back to one or more infection sites.)
Cave: All uninfected cells form one orthogonally connected area. Each orthogonally connected group of infected cells touches the grid's edge.
Detector Cells: A digit in a blue circle is uninfected and counts the number of infected cells in its 8 surrounding cells.
Germy Whispers lines connect 2 infected digits that differ by 5 or more.
Cocci Dots join consecutive uninfected digits.
Example Puzzle
A 6x6 example with the same rules and simplified styling. Colors: green for uninfected, red for inoculation sites, orange for other infected.
Solution code: Infected digits in column 6, top to bottom
Comments
on 11. November 2025, 01:36 by mscha
Harder than the first one. But very, very nice!
on 10. November 2025, 03:05 by silent_rob
Thanks for another fantastic puzzle in this series! It was great to have the previous rules as a foundation but then to tweak things with the cave rules. Looking forward to the next one!
on 8. November 2025, 04:51 by QuiltyAsCharged
Wonderful puzzle! For anyone curious, the term "inoculation" was correct for introducing a pathogen into a petri dish for study. However, since inoculation is associated with disease prevention in common usage, calling them "infection sites" may help to avoid confusion.
on 6. November 2025, 15:51 by gdc
rename "inoculation sites" to "infection sites"
on 5. November 2025, 21:33 by Christounet
Consider me infected ! Thanks :)
on 5. November 2025, 10:30 by Exigus
That was a great combination of constraints. Thanks!
on 3. November 2025, 12:05 by gdc
@zardoz37: I certainly don't want to promote any form of antiscience (like
anti-vaxx) with my puzzles.
The theme is that an uninfected petri dish is injected with viruses to study their reproduction behavior. Sorry if that was unclear.
on 3. November 2025, 04:55 by zardoz37
Loved the puzzle - not sure about the theme: inoculation leads to infection? Is this a puzzle for anti-vaxxers??
on 2. November 2025, 18:18 by ShadyAshley
This puzzle and the last one have been some of my absolute favorites recently. I love the theming and they have some really cool logic leading to constant epiphanies. Excellent setting, and I'm excited for the next one!!
on 2. November 2025, 14:32 by jakestilesowen
Incredibly good puzzle by all metrics. Thanks for it!
on 2. November 2025, 10:07 by Silverscree
I love a cave puzzle and I love a themed puzzle series. I'm eagerly awaiting future instalments!
on 1. November 2025, 22:35 by gdc
Fix typo in success message (thanks ViKingPrime!)
on 1. November 2025, 22:13 by ViKingPrime
A dokes a day keeps the doctor away! Even better than the first entry, which is saying something.
