The power struggle between Hassan al-Turabi, the Sudanese opposition politician, and his former ally Omar al-Bashir, the country's president, shows no signs of ending.
If anything, it could well be intensifying, judging by the late-night arrest on Saturday of al-Turabi.
He has been in and out of custody during his political career - one marked by remarkable shifts in allegiances.
In the last few years, while in the opposition, al-Turabi has been imprisoned or held under house arrest on several occasions.
His relationship with al-Bashir was, of course, not always antagonistic.
Indeed, they were very close in the past: al-Turabi was one of al-Bashir's most trusted advisers when the latter seized power in 1989.
Al-Turabi was then the chairman of al-Bashir's National Congress Party (NCP).
But the two split over the introduction of a bill to limit the president's powers in 1999, a move which al-Bashir countered by dissolvi