King Hussein shocked his subjects yesterday by departing, without warning, to the Mayo Clinic in the US where he has been receiving treatment for lymphatic cancer.
His doctors said he was suffering from fever and exhaustion.
Jordanians fear the worst and speculate on why he returned to his kingdom for only a week's stay.
They fear he has not been "cured" of non-Hodgkin's lymphoma, as he and his doctors claim, and wonder how they will manage without the monarch who has sat uneasily on the Hashemite throne for 47 years.
All too obviously, the king travelled to Amman to remove his younger brother, Crown Prince Hassan, as heir, a position he has held for 34 years.
In an uncharacteristically harsh letter sent to Prince Hassan, which was broadcast on Jordanian television, King Hussein criticised the crown prince for abusing power, stripping the army command of loyal officers and putting his own people in influential positions in the bureaucracy.
The king blamed Prince Hassan for the distribution of outdated medicines and the supply of polluted water to households in the capital which caused scandal last year.
And Prince Hassan was admonished for failing to condemn last month's Anglo-US bombing of Iraq and for not intervening with Palestinians and Israelis to secure implementation of the Wye River Memorandum, which King Hussein helped broker last October.
Prince Abdullah (37), the king's eldest son by his British wife, Mona, was named Crown Prince in a royal decree which was signed by King Hussein on Sunday, then leaked, rather than released, to the press.
Such behaviour was uncharacteristic of King Hussein who has a reputation for open and straightforward dealings with both his family and his people.
The dismissal of Prince Hassan, the elevation of Prince Abdullah and the king's departure have left Jordanians reeling. Speculators have come up with a number of explanations for the king's disturbing and destabilising actions.
The king, not expecting to live long, was alarmed about his brother's stewardship and feared for the survival of the Hashemite monarchy. Since the king is deeply committed to the survival of his dynasty, which goes back to 1201, he decided to remove Prince Hassan before serious damage was done.
The dying king was determined that one of his sons would follow him to the throne so he returned to remove Prince Hassan, who exercised power for the past 6 1/2 months, before he could consolidate his position.
Once Prince Hassan was removed, the king had to provide a prompt replacement. Prince Abdullah, originally named heir in 1963 when an infant, could be reinstated without amending the constitution.
So Prince Abdullah was the only possibility, although sources close to the palace had recently told The Irish Times that Prince Hamzah (19) was the king's choice. This, these sources said, is evidenced by the fact that Prince Abdullah could have replaced Prince Hassan at any time during the past decade, thereby gaining vital experience.
But Prince Abdullah was not the anointed heir: the king was keeping the throne for Prince Hamzah. However, to name him would have required constitutional changes and this would have taken time which, perhaps, the king does not have.
The king is said to have been cured of non-Hodgkin's lymphoma but, because his immune system has been undermined by chemotherapy, he was susceptible to catching a cold or flu virus during the long ride in an open car through the streets of his capital on his arrival on January 19th.
According to this explanation, Prince Abdullah may be a temporary heir, as Prince Hassan was when he was appointed in 1965 during a period of unrest. When and if King Hussein returns to Jordan and resumes his reign, he may elevate his favourite, Prince Hamzah, who has been groomed to succeed his father.
Although Jordanians do not expect a succession struggle within the ruling family, they are perplexed by the king's behaviour and fearful of a future without his strong and steady hand on the helm of the ship of state.