The Full and Terrible Truth

It seems from the get go The Carlyle Expedition was never about Egypt specifically but a cover for some conspiracy between the expedition members and an evil god, Nyarlathotep.
Roger Carlyle, seemingly under the sway of Nichonka Bunay made promises and threats to the various expedition members respectively to get them on board. Jack brady is known to have been inseparable from Roger Carlyle so would have followed him no matter what. Sir Aubrey Penhew was a known Egyptologist and had connections through his foundation so may not have required much encouragement to sign on. Hypatia Masters was known to have had some kind of scandal back in New York and may have simply wanted to escape rumours of an illicit relationship and a pregnancy terminated, willingly or no, and this may have made her to join her friend Roger to escape the salacious gossip columns of New York Society papers. Dr Huston was clearly blackmailed according to Dr Huston's Medical notes on Roger Carlyle ("If I do not go, C. threatens exposure.") and would likely have something to do with the suicide of Imelda Bosch, his lover.
The actual journey of the Expedition does appear to be genuine so far. New York to London, London to Cairo, Cairo to Mombasa and finally Nairobi before heading into the Great Rift Valley where the trail officially ends. The event surrounding the massacre of the Expedition have been exposed as only half true and local British authorities have affected a cover up of the events and hanged innocent men for the crime to keep the peace. Jack Brady has been confirmed to have been seen as recently as the 13th of March 1923 in Hong Kong by an old comrade Nails Nelson and doubts have been raised that no whites were found amongst the dead at the massacre site.
Events in Egypt have revealed that some kind of ritual took place at Dashur on the 30th of June 1919 (see Warren Besarts Account) and that the expedition members disappeared for a period of a day inside the Bent Pyramid at Meidum. The investigators have since confirmed the existence of a throne room dedicated to Nyarlathotep and evidence of a map in the room linking Kenya, Australia and China.

The other oddity in this investigation is the shipments from Darwin Australia. A series of shipments have been making their way to England via Shanghai and Cairo. These shipments have been ancient mechanical devices which then appear to have been copied and then those new components shipped to Shanghai. Ennio's experience with flying vehicles allowed him to at least partially decipher plans found in England that point to some kind of highly advanced flying machine but the purpose is as yet unknown.
Jackson Elias appears to have stumbled into this whole affair almost by accident, except for one piece of connective tissue. "M'Weru" the last word spoken by Augustus Larkin as he died in Peru. This appears in Dr Hustons Medical notes (He calls her M'Weru, Anastasia, and my priestess. He is obsessive about her, as well he might be-exterior devotion is certainly one way to ease the tensions of megalomaniacal contradiction. She is certainly a rival to my authority.) M'Weru was in fact Nichonka Bunay the "African Queen" whom Carlyle fell in love with in New York and seems to have orchestrated this whole affair.

The questions left unanswered

What happened to each of the Carlyle Expedition members? Their deaths are in question now that Jack brady has been sighted alive.

What are the components that are being shipped around the world and back again? How does a flying machine help the cults plans?

Where are the mechanical components that were being remade in England coming from exactly in Australia? They are ancient and must come from some unknown civilisation there.

What is with the cults in England, New York and Cairo having extremely modern maritime clocks?

How did the Cult find out about Jackson Elias investigation?