The producers of Star Trek Discovery have changed canon.

A Story by Richard

How do they explain the series that come after?

The Star Trek universe is set across three time lines. The events depicted in TOS, The Next Generation, Deep Space Nine, Voyager, Prodigy and possibly Picard take place in the first timeline. Those depicted in Enterprise, Discovery, Strange New Worlds and possibly Picard take place in the second timeline. The events of the three films, Star Trek, Star Trek Into Darkness and Star Trek Beyond take place in the third timeline, also known as the Kelvin timeline.

The divergence between the first and second timelines takes place in 2151. In the Next Generation episode “First Contact,” Captain Jean-Luc Picard describes first contact with the Klingon Empire as a disastrous event that led to decades of war¹. In the Enterprise pilot episode “Broken Bow,” first contact with the Klingons is shown when a Klingon warrior crashes in Broken Bow, Oklahoma in April 2151. The Klingon, Klaang, is fleeing from the Suliban, agents for one of many factions fighting a temporal cold war. These factions seek to alter history for their own benefit. Starfleet rescues the Klingon, and the crew of the USS Enterprise NX-01 returns him to Kronos. The Klingons then allow the humans to leave peacefully. Hardly the disastrous first encounter referred to by Captain Picard².

In April 2153, an alien probe attacks Earth, destroying a vast area from Florida to Venezuela. The Enterprise NX-01 scans the remains of the probe and finds a component with a date stamp placing construction at 420 years in the future. The probe has been sent by the Xindi, a previously unknown race, who have been informed by a Cold War faction that their home-world will be destroyed, in 400 years, by humans. At around the same time the crew of the Enterprise recover a small, badly damaged ship with the remains of a single occupant. Scans reveal that the occupant contains the DNA of multiple alien species, including human, and that much of the technology on board the ship is beyond the current level of development. It is determined that the ship and it's occupant must have come from the future³.

In 2155, the Klingons begin experimenting in genetic augmentation. They seem to have based their research off the work of Doctor Arik Soong, a human geneticist⁴. Unfortunately, the Klingon's experiments have unforeseen consequences, as the augmented DNA samples escape and mutant into a virus that eventually spreads throughout the empire. With the help of Doctor Phlox and Captain Archer they are able to develop a cure, although a side effect of the treatment means the Klingons loose their distinctive cranial ridges⁵.

We see that, as depicted in Star Trek: Enterprise, first contact with the Klingons was not the disastrous event referred to by Captain Picard. Instead, it was the result of interference by elements from the future seeking to alter the time line. Had this temporal incursion not occurred, other events would have played out instead. That is, the event referred to by Captain Picard that led directly to decades of war between Starfleet and the Klingon Empire. This establishes that the events seen in Star Trek:Enterprise are not a precursor to Star Trek: TOS and the series that followed, but are part of an alternate time line created by multiple instances of interference from the future.

Looking at Star Trek: Discovery, we see that it contains many inconsistencies with Star Trek: TOS and the series that came later. Ship and uniform designs are different to what they should be for this era, which is only around fifteen to twenty years prior to the period in which TOS is set. There is holosuite and holo-communication technology, although this technology was not developed until The Next Generation era and later. Klingon physical characteristics are not only different to the TOS era, but also the The Next Generation. These inconsistencies are explained once we understand that Star Trek: Discovery continues within the timeline established by Star Trek: Enterprise.

We know that technology from the future was recovered by the Enterprise NX-01 in 2153. It is reasonable to assume that other Starfleet vessels also retrieved similar technology, as did other races. This technology would no doubt have been reverse engineered and integrated into future developments. This would explain holo-technology on Starfleet ships, Klingon ships with cloaking devices, and other technology that was not available during the TOS era. Differences in the architecture and design between Star Trek: Discovery and TOS, such as uniform and ship design, can also be explained by the Temporal Cold War. There would have been a large number of casualties among the contemporary population of the 22^nd Century. Directly, in the case of the Xindi attack on Earth, as well as indirectly. It is reasonable to assume that, in the original time line, some of these individuals would have been involved in the design of uniforms, ships and other technology. In this new, alternate timeline different designers would result in different designs. The extent to which these designs differ to the original would depend on how many of the original designers, from the original timeline, were still involved.

Finally, the differences between the Klingons of the first time line, and those in Star Trek: Discovery. We see in the Star Trek: Enterprise episode Divergence how the augmentation virus led to the lose of the Klingon cranial ridges. This in itself does not seem to have been influenced by the Temporal Cold War, so it is logical to assume that the same events led to the lose of Klingon cranial ridges in the first timeline. The difference between the two time lines, in regards to the physical characteristics of the Klingons, seems to occur some time between the end of Star Trek: Enterprise (circa. 2153) and the beginning of Star Trek: Discovery. Star Trek: Discovery is set ten years prior to Star Trek: TOS, yet the Klingons once again have cranial ridges. However, many of them also have different skin colourings and all lack hair. Some of these changes have been explained within the series. The Klingons we see within Discovery are from a different sect to those we have seen before, and follow different customs. These Klingons shave their heads during times of war. But how does this explain the different skin colours, and the return of cranial ridges a hundred years before they were first seen in Star Trek: The Motion Picture? The only explanation is that something countered the effects of the augmentation virus in the second timeline a hundred years early. We have already shown that improvements in technology were made using salvaged material from the Temporal Cold War. It seems logical that similar improvements would also have been made in science and medicine. The Enterprise crew recovered the body of a time traveller from the future. It would seem that the Klingons also made similar discoveries, and that they used these to continue their research into the augmentation virus. These experiments seem to have brought them closer to restoring their original physical characteristics, bringing back their original cranial ridges but altering traits such as skin colour and complexion.