This article contains a list of all theories that would bring about The End of Time.
Wave destroys the castle(s)
Few claim the water level changes over time; few claim pixels appear over the horizon.
As of April the 18th, 2013, the water level has risen significtantly, going so far as to start to damage the castle.
BHG shows up (Time traveling theory connecting comics #1190 & #1191)
Perhaps having to build yet another one-shot time machine to visit the pre-industrialized past — counting on easily drilling for oil in a foreign country since any opposition or military involvement would not yet exist. The panel has a conspicuous cold-open, and ends with BHG's words trailing off in thought with a schemingly sounding, "Hmmm...". The alt-text also feels particularly foreshadowing to this theory.
At some point, in a future comic, we should see BHG vanishing into the past, and excitingly, he appears in the previous panel "Time" coinciding with the very next newpic.
If so, we'll have had the luxury to see how The Past has been unfolding in all these interveining newpix in "Time" (1190), understanding what BHG will not be prepared for. Assuming typical BHG fashion, he's underestimating the past's outdated military, because Cueball and Megan have certainly been busy: Building sandcastles; using a trebuchet to destroy them; creating mounds to try and get a better vantage of their surroundings; creating a small scale layout of their newly created structures to use, as a military general might, to plan a seige on a war room table (and even placing a miniature trebuchet within it!).
We also get to see subtle clues in leading up to all this. They decide go for a swim in perhaps less than ideal sea water, causing Megan to choke and cough a little. Could it be tainted with crude oil? Also, Megan, pensively observing the sea level, doesn't seem to understand the rising tides, and Cueball remains silent. Suggesting this scientific knowledge must be after their time? They come and go as they please, playing, building, and experimenting, until Megan, probably thirsty or needing to bathe, asks where the river is. Most likely due to not having modern conveniences such as plumbing? Also, this would indicate an arid, desert climate with fresh water levels rising and falling in regions of the world now known for massive amounts of crude oil and fossil fuels not far below the ground.
And finally, Cueball, reaching the limit of his inventiveness, believes their creations can't be built any bigger or taller. He leaves Megan seemingly challanged by this departing declaration, and immediately puts her proven ingenuity to work, attempting something much grander which Cueball couldn't conceive.
If this theory plays out, BHG might arrive unwittingly too late, (as in the comic "Kill Hitler" ), where he succeeds in killing the Führer, but foolishly does so in 1945, near the end of WWII, making it totally pointless and wasting his one-shot time machine.
In theory, by the time he arrives in "Time", he should be in for quite a surprise when he finds out what Megan and Cueball have been up to...
Ends with the Series
This comic is the last comic in the series and will have an unimaginably epic ending. Some panic that Randall will soon end his comic series whenever he produces a comic that is too epic. Similar fears were expressed after Click and Drag. This theory was debunked with comic 1191
Red Spiders Cometh, from 126.
Castle(s) slowly erode
Somehow loops back to start frame
Ends with an April Fool's day joke
The comic publishes exactly one week before April Fool's day. This theory has been debunked by new frames still being added on April 2nd.
Goes on for months (maybe forever)
One of the first end-of-comic theories, the Goes on for Months (Maybe Forever) theory has undergone several minor revisions, yet remains a major possibility regarding the future of Time. Many (often arbitrary) speculations have been made concerning the length of time required to produce each picture, how long in the past Randall the Almighty may have begun creating them and how much time it would take him to make a week's worth in the future, and from those factors have extrapolated the duration of time the comic could presumably go on for.
Big build up for comic #1200
Should come on April 17. Disproven as the comic continues past April 17th, continung to drive its followers deeper into a never ending madness of when and how will the end of Time come.
Wait for it
- Main article: Wait for it
Wait for it...
Comic zooms in on a scale model of the sandcastle, currently being constructed by Cueball ... and then does it again!
Debunked after Cueball and Megan left on their journey.
The Frame devourers everything
As seen in OtherComic #82.
The slowly rising tide continues to rise, washing over the castle. To combat the rising tide Megan built a small dam, and then a large platform was constructed. This may prove insufficient to stop the effects of the tide, which might eventually cover the entire comic.
Doctor Who 50th anniversary tribute
The comic started on March 25th, which was the date of the first UK airing of the new series of Doctor Who, which is about time travel. If the comic is Randall's tribute to the show, it may end on November 23rd, the 50th anniversary of the first ever airing. (The alt-text changing to "RUN." might be taken as supporting this as well ...)