G'Tach

G'Tach is the Hebrew word that collectively refers to the ten plagues visited upon Egypt by God to persuade the Pharaoh to release Moses and his people from bondage.

The ten plagues

 * 1) Dam &mdash; all sources of fresh water were turned to blood.
 * 2) Tsfardeia &mdash; the land was overrun by frogs.
 * 3) Kinim &mdash; Egypt was infested with swarms of fleas.
 * 4) Arov &mdash; Egyptians and livestock were attacked by stinging and biting flies.
 * 5) Dever &mdash; a pestilence throughout the livestock of the Egyptians.
 * 6) Shkhin &mdash; the Egyptians were afflicted with painful boils.
 * 7) Barad &mdash; fiery hail pelted the land.
 * 8) Arbeh &mdash; the plague of locusts.
 * 9) Choshech &mdash; the land was blanketed by unending darkness.
 * 10) Makat Bechorot &mdash; the death of all the firstborn males.  All first born males of every household (including farm animals) were slain if the household did not mark the door with the blood of a sacrificial lamb (Passover).

Historical evidence
There is no evidence that the Hebrews were ever slaves in Egypt, or indeed that they escaped in a mass exodus, and no records at all of the above series of catastrophes. Although different scholars have presented various theories about the historicity of the Exodus, such as identifying the Hebrews with the Hyksos people, the archaeological evidence rather suggests that the story is a narrative which recalls the move from nomadism to sedentism by the early Hebrews.

It has been suggested that the Egyptians would have been reluctant to record a slave revolt which was pretty much entirely successful, as this would have been a rather humiliating experience. Count in how much influence the Egyptian priests had in that time, when it seem like their gods, who are supposed to be, well, all powerful, do absolutely nothing to stop what is apparently the wrath of a god worshiped by said slaves, it becomes possible that the priests could have outright had it completely denied as ever happening and covered it up in a sort of North Korea manner. Of course, that doesn't explain why none of their neighbors caught wind of it.

The Ipuwer papyrus
Some historians of biblical bent have found much to interest them in the Ipuwer papyrus, an Egyptian poem describing a series of disasters that befell Egypt in ancient times. Some people who ought to know better suggest that this document describes the G'tach, despite the work describing the fall of the Old Kingdom (ca. 2200 BCE), and its composition dating to the early Middle Kingdom (ca. 1900 BCE), long before the New Kingdom, in which the Exodus is said to have occurred (either 1446 BCE or ca. 1260 BCE). Only advocates of alternate historical chronology could possibly use this as evidence.

As Gordon Zellaby put it in John Wyndham's novel  "For my part, I regard the plagues of Egypt as an unedifying example of celestial bullying; a technique now known as power-politics."

"Scientific" explanations
There have been numerous attempts at providing scientific explanations for the plagues. Some events, such as plagues of locusts, are common, but others require more creative powers. This ignores the facts that the plagues aren't the only improbable bit of the story, the lack of detail about the plagues, and how some of the explanations do not accord with details of the Biblical story. Nonetheless, it may be that real events influenced the people who made up the plague narratives, or that the Biblical story interleaves mythical versions of other natural disasters.

River of blood: was this perhaps a red algal bloom? These can be toxic and produce foul vapors. Most people could tell the difference between them and blood.

Plague of frogs: there is no real explanation, but there are phenomena involving frogs (or toads), both raining frogs and mass movements of frogs (or toads).

Plague of boils: might have been smallpox, which is known to have existed around 1000 BCE based on smallpox scars on mummies. This still doesn't quite fit the Biblical chronology, but would make sense if the narrative was made up later and they were thinking about bad shit that they'd seen.

Fiery hail: could have been connected with a volcanic eruption. There certainly were some in the eastern Mediterranean, such as Santorini around 1500 BCE. A meteor impact has also sometimes been proposed as an explanation.

Plague of locusts: desert locusts can be incredibly damaging to agriculture. Normally, they are solitary, but in certain conditions, they form swarms, multiply very quickly, and eat a lot. Such plagues are still seen across many parts of Africa. A plague of locusts is plausible, although there is no evidence that Moses was involved.

Darkness: this has been blamed on a solar eclipse, but that would not provide 3 days of darkness, with totality typically lasting 1-2 minutes and partial eclipse less than 90 minutes. It has also been attributed to clouds of ash from a volcanic eruption darkening the sky, which would connect it to the fiery hail.

Killing of the firstborn: there is no disease that kills firstborn children, so this is obviously problematic. It has been suggested that firstborn children might have been the ones to work in the fields and hence have been most affected by any toxins created by volcanoes, plant disease, mycotoxins, etc. This is all very speculative. And the killing of the firstborn is one of the least plausible parts of the narrative, requiring direct divine intervention. So probably not one you can explain by anything other than incredible exaggeration or outright fabrication.