What links Bo Xilai and Chen Guangcheng, beyond the fact that they have both posed huge challenges to the Communist Party's powers of crisis management? The first is a mighty figure who, it seems, has been felled after allowing his ambition to reach too far. The other is a member from one of the most disadvantaged, voiceless groups in Chinese society - the rural disabled. One came from party aristocracy; the other was a self-taught lawyer who didn't even have the chance to go to university and started his career working in medical massage.
As two figures capturing the ends of the social spectrum in China, Bo and Chen are perfect. The handling of their very different cases has raised sharp questions about how the party is trying to govern, how it is trying to achieve its leadership transition, and how it can become, in its own words, a party at the vanguard of modernisation. After all, China is aiming, as it has done since the foundation of the People's Republic in 1949, to be a 'rich strong country'.
At heart, in fact, the two cases highlight the great challenges of governance in contemporary China. The issue is how justice can be dispensed in an authoritarian regime: in this instance, the world's last major state with a ruling Communist Party. The People's Daily, in a series of recent editorials, talked of no one being above the law in China, of everyone being treated fairly. For both Bo and Chen, one might argue that this is exactly the problem.
Bo was overbearing, brutal and showed scant regard for legality in his campaigns in Chongqing against organised crime. But his removal from office, and how he is to be treated now, will show just how far the party's governance has changed. Under Hu Jintao, the party has tried to institutionalise the ways in which it actually exercises power.
Will the party's Central Commission for Discipline Inspection now be able to present a prosecution that can be convincingly sold to the public as based on credible proof of foul play by Bo? Or will the overwhelming impression be that this is a case where politics has been in command from beginning to end? The public view may well be that justice is not the key issue here but delivering political goals in a tricky moment.
Chen Guangcheng, in his extraordinary battles with local security agents since his release from prison in 2010, and his fleeing to the US embassy, also raises issues of how justice can really be dispensed in a country where there are vested interests and conflicting chains of command, and where courts are struggling in a sea of contending litigants and against party actors who are very nervous at where legal challenges might lead.
In his testimony posted on YouTube just after fleeing his village in Shandong, Chen addressed Premier Wen Jiabao directly, and named specific officials, asking for investigation. He has since been interviewed by party discipline investigators. Can the party, at least at the central level, convincingly show that they have the political and administrative will now to hold local officials to account, and at least offer some semblance of a public investigation into claims of wrongdoing and illegality?
China's challenges in the next few years are predominantly seen in terms of managing huge economic imbalances, dealing with issues of sustainability, maintaining stability and making the transition to a middle-income country by 2020. But these two cases - of a person once very powerful, and the other at the opposite end of the power spectrum - show that the real challenge is how justice is dispensed.
As China has grown richer, it has grown more contentious. Social media, as is clear from the key role it has played over the last few weeks in the discussion of both of these cases, is creating new levels of awareness of problems and complaints. The party can no longer just cover things up and impose a curfew of silence.
Chen and Bo share a profound characteristic: despite advocating change, neither challenged the legitimacy of the party to rule. Chen certainly raised severe issues about the ways in which it ruled, but has never questioned its right to do so. Bo was less concerned with procedure and more with socially redistributive outcomes.
Remarkably though, key players in both cases involved the US, suggesting that they did not think they would get fair treatment within China. This appeal for justice to an external authority should worry the leadership of the party. Like luxury goods and hi-tech imports, justice for some Chinese is still seen as something best sourced abroad.
The current situation has one major possible outcome. It should worry and wake up enough figures in the leadership of the party to the critical need for better means to deliver justice and accountability. And that, like it or not, means a more empowered legal sector, better functioning and funded courts, and lawyers who are given enough power to, from time to time, truly challenge officials.
The legitimacy of responsible government disappears rapidly when the officials who run the system fail to act responsibly. And the rest of the world surely has a role in trying to help China achieve this.
Kerry Brown will take up a position as professor and director of the China Studies Centre at Sydney University this summer. David Goodman is professor of contemporary China and academic director there