This investor's campaign is stoking some undesirable corporate intrigue.What a twist! An activist investment fund, Starboard Value, has recently been pushing Pfizer (PFE -0.27%) to increase shareholder value. Though they initially supported its campaign, Pfizer's former chief executive officer and chief financial officer both made a late-night about-face on Oct. 9, publicly pledging instead to support the current CEO, Albert Bourla. Now, Starboard's $1 billion stake in the limping pharma juggernaut may mean ...