A cause of action for legal malpractice is in the nature of a tort and, thus, is governed by the two-year limitations statute. First National Bank v. Levine, 721 S.W.2d 287 (Tex. 1986). For a suit to be timely under the two-year statute, it must be brought within two years following the date the cause of action accrues. TEX. CIV. PRAC. & REM. CODE ANN. 16.003(a) (Vernon Supp. 2000). A cause of action accrues when a wrongful act causes some legal injury, even if the fact of injury is not discovered until later, and even if all resulting damages have not yet occurred. Murphy v. Campbell, 964 S.W.2d 265, 270 (Tex. 1997). The legal injury rule is not without exception, however, and sometimes an action does not accrue until the plaintiff knew or in the exercise of reasonable diligence should have known of the wrongful act and resulting injury. Id. This exception, called the "discovery rule," applies in cases of fraud and fraudulent concealment and in other cases in which the nature of the injury incurred is inherently undiscoverable and the evidence of injury is objectively verifiable. Id. To be "inherently undiscoverable," an injury need not be absolutely impossible to discover, else suit would never be filed and the question whether to apply the discovery rule would never arise. Id.; S.V. v. R.V., 933 S.W.2d 1, 7 (Tex. 1996). Nor does "inherently undiscoverable" mean merely that a particular plaintiff did not discover his injury within the prescribed period of limitations; discovery of a particular injury is dependent not solely on the nature of the injury but on the circumstances in which it occurred and the plaintiff's diligence as well. Murphy, 964 S.W.2d at 270; S.V., 933 S.W.2d at 7. An injury is inherently undiscoverable if it is by nature unlikely to be discovered within the prescribed limitations period despite due diligence. Murphy, 964 S.W.2d at 270; S.V., 933 S.W.2d at 7.